diff --git a/Github/building-base.py b/Github/building-base.py
new file mode 100644
index 0000000..17213cd
--- /dev/null
+++ b/Github/building-base.py
@@ -0,0 +1,47 @@
+class Building:
+    def __init__(self, south, west, width_WE, width_NS, height=10):
+        self.x = west
+        self.y = south
+        self.width = width_WE
+        self.height = width_NS
+        self.depth = height
+
+    def corners(self):
+        return {
+            "south-west": [self.y, self.x],
+            "south-east": [self.y, self.x + self.width],
+            "north-west": [self.y + self.height, self.x],
+            "north-east": [self.y + self.height, self.x + self.width],
+        }
+
+    def area(self):
+        return self.width * self.height
+
+    def volume(self):
+        return self.area() * self.depth
+
+    def __repr__(self):
+        return "Building({}, {}, {}, {}, {})".format(
+            self.y,
+            self.x,
+            self.width,
+            self.height,
+            self.depth
+        )
+
+
+if __name__ == '__main__':
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+    def json_dict(d):
+        return dict((k, list(v)) for k, v in d.items())
+
+
+    b = Building(1, 2, 2, 3)
+    b2 = Building(1, 2, 2, 3, 5)
+    assert b.area() == 6, "Area"
+    assert b.volume() == 60, "Volume"
+    assert b2.volume() == 30, "Volume2"
+    assert json_dict(b.corners()) == {'north-east': [4, 4], 'south-east': [1, 4],
+                                      'south-west': [1, 2], 'north-west': [4, 2]}, "Corners"
+
+    assert str(b) == "Building(1, 2, 2, 3, 10)", "String"
diff --git a/Github/conversion-from-camelcase.py b/Github/conversion-from-camelcase.py
new file mode 100644
index 0000000..0fb4458
--- /dev/null
+++ b/Github/conversion-from-camelcase.py
@@ -0,0 +1,22 @@
+def from_camel_case(name):
+    new_name = ""
+    for i, letter in enumerate(name):
+        if i == 0:
+            new_name += letter.lower()
+        elif letter.lower() != letter:
+            new_name += "_"+letter.lower()
+        else:
+            new_name += letter
+    return new_name
+
+
+if __name__ == '__main__':
+    print("Example:")
+    print(from_camel_case("Name"))
+
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+    assert from_camel_case("MyFunctionName") == "my_function_name"
+    assert from_camel_case("IPhone") == "i_phone"
+    assert from_camel_case("ThisFunctionIsEmpty") == "this_function_is_empty"
+    assert from_camel_case("Name") == "name"
+    print("Coding complete? Click 'Check' to earn cool rewards!")
diff --git a/Github/every-person-is-unique.py b/Github/every-person-is-unique.py
new file mode 100644
index 0000000..8bfff44
--- /dev/null
+++ b/Github/every-person-is-unique.py
@@ -0,0 +1,48 @@
+from datetime import datetime
+import math
+
+
+class Person:
+    def __init__(self, first_name, last_name, birth_date, job, working_years, salary, country, city, gender='unknown'):
+        self.first_name = first_name
+        self.last_name = last_name
+        self.birth_date = birth_date
+        self.job = job
+        self.working_years = working_years
+        self.salary = salary
+        self.country = country
+        self.city = city
+        self.gender = gender
+
+    def name(self):
+        return "{} {}".format(self.first_name, self.last_name)
+
+    def age(self):
+        d1 = datetime.strptime(self.birth_date, "%d.%m.%Y")
+        # d2 = datetime.now()
+        d2 = datetime.strptime("01.01.2018", "%d.%m.%Y")
+        return math.floor(abs((d2 - d1).days) / 365)
+
+    def work(self):
+        return "{} a {}".format(
+            "He is" if self.gender == "male" else "She is" if self.gender == "female" else "Is",
+            self.job)
+
+    def money(self):
+        return f'{self.salary * 12 * self.working_years:,}'.replace(",", " ")
+
+    def home(self):
+        return "Lives in {}, {}".format(self.city, self.country)
+
+
+if __name__ == '__main__':
+    #These "asserts" using only for self-checking and not necessary for auto-testing
+
+    p1 = Person("John", "Smith", "19.09.1979", "welder", 15, 3600, "Canada", "Vancouver", "male")
+    p2 = Person("Hanna Rose", "May", "05.12.1995", "designer", 2.2, 2150, "Austria", "Vienna")
+    assert p1.name() == "John Smith", "Name"
+    assert p1.age() == 40, "Age"
+    assert p2.work() == "Is a designer", "Job"
+    assert p1.money() == "648 000", "Money"
+    assert p2.home() == "Lives in Vienna, Austria", "Home"
+    print("Coding complete? Let's try tests!")
diff --git a/Github/flatten-dict.py b/Github/flatten-dict.py
new file mode 100644
index 0000000..9de9f2e
--- /dev/null
+++ b/Github/flatten-dict.py
@@ -0,0 +1,56 @@
+def flatten(dictionary, children=None):
+    if children is None:
+        children = []
+    new_dict = {}
+    for name, value in dictionary.items():
+        if isinstance(value, dict):
+            if len(value) != 0:
+                children.append(name)
+                new_dict.update(flatten(value, children))
+                children.pop()
+            elif len(children) == 0:
+                new_dict[name] = ""
+            else:
+                new_dict["/".join(children) + "/" + name] = ""
+        elif len(children) == 0:
+            new_dict[name] = value
+        else:
+            new_dict["/".join(children) + "/" + name] = value
+    return new_dict
+
+
+if __name__ == '__main__':
+    test_input = {"key": {"deeper": {"more": {"enough": "value"}}}}
+    print(' Input: {}'.format(test_input))
+    print('Output: {}'.format(flatten(test_input)))
+
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+    assert flatten({"key": "value"}) == {"key": "value"}, "Simple"
+    assert flatten(
+        {"key": {"deeper": {"more": {"enough": "value"}}}}
+    ) == {"key/deeper/more/enough": "value"}, "Nested"
+    assert flatten({"empty": {}}) == {"empty": ""}, "Empty value"
+    assert flatten({"name": {
+        "first": "One",
+        "last": "Drone"},
+        "job": "scout",
+        "recent": {},
+        "additional": {
+            "place": {
+                "zone": "1",
+                "cell": "2"}}}
+    ) == {"name/first": "One",
+          "name/last": "Drone",
+          "job": "scout",
+          "recent": "",
+          "additional/place/zone": "1",
+          "additional/place/cell": "2"}
+    var = {"job/1": "scout", "recent/places/earth/NY": "2017", "job/3": "writer", "job/2": "worker", "job/5": "learner",
+           "job/4": "reader", "recent/places/earth/NP": "", "recent/places/earth/Louvre": "2015",
+           "recent/times/XX/1964": "Yes", "recent/times/XXI/2064": "Nope", "name/first": "Second", "name/last": "Drone",
+           "name/nick": ""}
+    assert flatten({"name": {"first": "Second", "last": "Drone", "nick": {}},
+                    "job": {"1": "scout", "2": "worker", "3": "writer", "4": "reader", "5": "learner"},
+                    "recent": {"places": {"earth": {"Louvre": "2015", "NY": "2017", "NP": ""}},
+                               "times": {"XX": {"1964": "Yes"}, "XXI": {"2064": "Nope"}}}}) == var
+    print('You all set. Click "Check" now!')
diff --git a/Github/loading-cargo.py b/Github/loading-cargo.py
new file mode 100644
index 0000000..4b59072
--- /dev/null
+++ b/Github/loading-cargo.py
@@ -0,0 +1,26 @@
+import itertools
+
+
+def best_balance(stoneset):
+    balances = []
+    for i in range(1, len(stoneset)):
+        left = stoneset[0:-(len(stoneset) - i)]
+        right = stoneset[i:len(stoneset)]
+        balances.append(abs(sum(left) - sum(right)))
+    return min(balances)
+
+
+def checkio(stones):
+    if len(stones) == 1:
+        return stones[0]
+    return min(set(map(best_balance, list(itertools.permutations(stones)))))
+
+
+if __name__ == '__main__':
+    assert checkio([10, 10]) == 0, 'First, with equal weights'
+    assert checkio([10]) == 10, 'Second, with a single stone'
+    assert checkio([5, 8, 13, 27, 14]) == 3, 'Third'
+    assert checkio([5, 5, 6, 5]) == 1, 'Fourth'
+    assert checkio([12, 30, 30, 32, 42, 49]) == 9, 'Fifth'
+    assert checkio([1, 1, 1, 3]) == 0, "Six, don't forget - you can hold different quantity of parts"
+    print('All is ok')
\ No newline at end of file
diff --git a/Github/voice-tv-control.py b/Github/voice-tv-control.py
new file mode 100644
index 0000000..ca8d49a
--- /dev/null
+++ b/Github/voice-tv-control.py
@@ -0,0 +1,55 @@
+class VoiceCommand:
+    def __init__(self, channels):
+        self.channels = channels
+        self.current = 0
+
+    def first_channel(self):
+        self.current = 0
+        return self.channels[0]
+
+    def last_channel(self):
+        self.current = len(self.channels) - 1
+        return self.channels[self.current]
+
+    def turn_channel(self, channel):
+        self.current = channel - 1
+        return self.current_channel()
+
+    def next_channel(self):
+        self.current += 1
+        if self.current >= len(self.channels):
+            self.current = 0
+        return self.current_channel()
+
+    def previous_channel(self):
+        self.current -= 1
+        if self.current < 0:
+            self.current = len(self.channels) - 1
+        return self.current_channel()
+
+    def current_channel(self):
+        return self.channels[self.current]
+
+    def is_exist(self, channel):
+        if isinstance(channel, int):
+            return "Yes" if 0 <= channel < len(self.channels) else "No"
+        else:
+            return "Yes" if channel in self.channels else "No"
+
+
+if __name__ == '__main__':
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+
+    CHANNELS = ["BBC", "Discovery", "TV1000"]
+
+    controller = VoiceCommand(CHANNELS)
+
+    assert controller.first_channel() == "BBC"
+    assert controller.last_channel() == "TV1000"
+    assert controller.turn_channel(1) == "BBC"
+    assert controller.next_channel() == "Discovery"
+    assert controller.previous_channel() == "BBC"
+    assert controller.current_channel() == "BBC"
+    assert controller.is_exist(4) == "No"
+    assert controller.is_exist("TV1000") == "Yes"
+    print("Coding complete? Let's try tests!")
diff --git a/OReilly/cipher-map2.py b/OReilly/cipher-map2.py
new file mode 100644
index 0000000..fe32341
--- /dev/null
+++ b/OReilly/cipher-map2.py
@@ -0,0 +1,32 @@
+def recall_password(cipher_grille, ciphered_password):
+    password = ""
+    for rotation in range(4):
+        for i, row in enumerate(cipher_grille):
+            for j, cell in enumerate(row):
+                if cell == "X":
+                    password += ciphered_password[i][j]
+        cipher_grille = list(zip(*cipher_grille[::-1]))
+    return password
+
+
+if __name__ == '__main__':
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+    assert recall_password(
+        ('X...',
+         '..X.',
+         'X..X',
+         '....'),
+        ('itdf',
+         'gdce',
+         'aton',
+         'qrdi')) == 'icantforgetiddqd', 'First example'
+
+    assert recall_password(
+        ('....',
+         'X..X',
+         '.X..',
+         '...X'),
+        ('xhwc',
+         'rsqx',
+         'xqzz',
+         'fyzr')) == 'rxqrwsfzxqxzhczy', 'Second example'
diff --git a/OReilly/create-intervals.py b/OReilly/create-intervals.py
new file mode 100644
index 0000000..f6c51e2
--- /dev/null
+++ b/OReilly/create-intervals.py
@@ -0,0 +1,29 @@
+def create_intervals(data: set):
+    """
+        Create a list of intervals out of set of ints.
+    """
+    if len(data) == 0:
+        return []
+    results = []
+    data = sorted(data)
+    start = None
+    current_number = None
+    for number in data:
+        if start is None:
+            start = number
+            current_number = start
+            continue
+        if number != start and number != (current_number + 1):
+            results.append((start, current_number))
+            start = number
+        current_number = number
+    results.append((start, current_number))
+    return results
+
+
+if __name__ == '__main__':
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+    assert create_intervals({1, 2, 3, 4, 5, 7, 8, 12}) == [(1, 5), (7, 8), (12, 12)], "First"
+    assert create_intervals({1, 2, 3, 6, 7, 8, 4, 5}) == [(1, 8)], "Second"
+    assert create_intervals({7, 9, 10, 11, 12}) == [(7, 7), (9, 12)], "Third"
+    print('Almost done! The only thing left to do is to Check it!')
diff --git a/OReilly/days-diff.py b/OReilly/days-diff.py
new file mode 100644
index 0000000..1d58447
--- /dev/null
+++ b/OReilly/days-diff.py
@@ -0,0 +1,21 @@
+from datetime import datetime
+
+
+def days_diff(a, b):
+    [a_year, a_month, a_days] = list(map(str, a))
+    [b_year, b_month, b_days] = list(map(str, b))
+    d1 = datetime.strptime("{}-{}-{}".format(a_year.rjust(4, "0"), a_month.rjust(2, "0"), a_days.rjust(2, "0")), "%Y-%m-%d")
+    d2 = datetime.strptime("{}-{}-{}".format(b_year.rjust(4, "0"), b_month.rjust(2, "0"), b_days.rjust(2, "0")), "%Y-%m-%d")
+    return abs((d2 - d1).days)
+
+
+if __name__ == '__main__':
+    print("Example:")
+    print(days_diff((1982, 4, 19), (1982, 4, 22)))
+
+    # These "asserts" are used for self-checking and not for an auto-testing
+    assert days_diff((1982, 4, 19), (1982, 4, 22)) == 3
+    assert days_diff((2014, 1, 1), (2014, 8, 27)) == 238
+    assert days_diff((2014, 8, 27), (2014, 1, 1)) == 238
+    assert days_diff([1, 1, 1], [9999, 12, 31]) == 3652058
+    print("Coding complete? Click 'Check' to earn cool rewards!")
diff --git a/OReilly/median.py b/OReilly/median.py
new file mode 100644
index 0000000..2139209
--- /dev/null
+++ b/OReilly/median.py
@@ -0,0 +1,30 @@
+from typing import List
+import math
+
+
+def checkio(data: List[int]) -> [int, float]:
+    data.sort()
+    data_len = len(data)
+    if data_len % 2 == 0:
+        if data_len != 2:
+            cut = int(data_len / 2 - 1)
+            data = data[cut:-cut]
+        return sum(data) / len(data)
+    middle = math.floor(data_len / 2)
+    return data[middle]
+
+
+# These "asserts" using only for self-checking and not necessary for auto-testing
+if __name__ == '__main__':
+    print("Example:")
+    print(checkio([1, 2, 3, 4, 5]))
+
+    assert checkio([1, 2, 3, 4, 5]) == 3, "Sorted list"
+    assert checkio([3, 1, 2, 5, 3]) == 3, "Not sorted list"
+    assert checkio([1, 300, 2, 200, 1]) == 2, "It's not an average"
+    assert checkio([3, 6, 20, 99, 10, 15]) == 12.5, "Even length"
+    print("Start the long test")
+    assert checkio(list(range(1000000))) == 499999.5, "Long."
+    assert checkio([10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0]) == 5, "5."
+    assert checkio([999999, 1]) == 5, "5."
+    print("Coding complete? Click 'Check' to earn cool rewards!")
diff --git a/OReilly/text-editor.py b/OReilly/text-editor.py
new file mode 100644
index 0000000..4b7750b
--- /dev/null
+++ b/OReilly/text-editor.py
@@ -0,0 +1,51 @@
+import copy
+
+
+class Text:
+    def __init__(self):
+        self.lines = ""
+        self.font = ""
+
+    def write(self, lines):
+        self.lines += lines
+
+    def set_font(self, font_name):
+        self.font = font_name
+
+    def show(self):
+        return "[{}]{}[{}]".format(self.font, self.lines, self.font) if self.font != "" else self.lines
+
+    def restore(self, version):
+        self.font = version.font
+        self.lines = version.lines
+
+
+class SavedText:
+    def __init__(self):
+        self.texts = []
+
+    def save_text(self, texts):
+        self.texts.append(copy.deepcopy(texts))
+
+    def get_version(self, version):
+        return self.texts[version]
+
+
+if __name__ == '__main__':
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+
+    text = Text()
+    saver = SavedText()
+
+    text.write("At the very beginning ")
+    saver.save_text(text)
+    text.set_font("Arial")
+    saver.save_text(text)
+    text.write("there was nothing.")
+
+    assert text.show() == "[Arial]At the very beginning there was nothing.[Arial]"
+
+    text.restore(saver.get_version(0))
+    assert text.show() == "At the very beginning "
+
+    print("Coding complete? Let's try tests!")
diff --git a/OReilly/worth-of-words.py b/OReilly/worth-of-words.py
new file mode 100644
index 0000000..3877851
--- /dev/null
+++ b/OReilly/worth-of-words.py
@@ -0,0 +1,33 @@
+VALUES = {'e': 1, 'a': 1, 'i': 1, 'o': 1, 'n': 1, 'r': 1,
+          't': 1, 'l': 1, 's': 1, 'u': 1, 'd': 2, 'g': 2,
+          'b': 3, 'c': 3, 'm': 3, 'p': 3, 'f': 4, 'h': 4,
+          'v': 4, 'w': 4, 'y': 4, 'k': 5, 'j': 8, 'x': 8,
+          'q': 10, 'z': 10}
+
+
+def worth_of_words(words):
+    highest_word = None
+    highest_score = 0
+    for word in words:
+        score = word_score(word)
+        if score > highest_score:
+            highest_score = score
+            highest_word = word
+    return highest_word
+
+
+def word_score(word):
+    score = 0
+    for letter in word:
+        score += VALUES[letter]
+    return score
+
+
+if __name__ == '__main__':
+    print("Example:")
+    print(worth_of_words(['hi', 'quiz', 'bomb', 'president']))
+
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+    assert worth_of_words(['hi', 'quiz', 'bomb', 'president']) == 'quiz'
+    assert worth_of_words(['zero', 'one', 'two', 'three', 'four', 'five']) == 'zero'
+    print("Coding complete? Click 'Check' to earn cool rewards!")