diff --git a/Dropbox/3-chefs.py b/Dropbox/3-chefs.py
new file mode 100644
index 0000000..4447064
--- /dev/null
+++ b/Dropbox/3-chefs.py
@@ -0,0 +1,66 @@
+class AbstractCook:
+    def __init__(self):
+        self.food_name = ""
+        self.drink_name = ""
+        self.food = 0
+        self.drink = 0
+
+    def add_food(self, amount, price):
+        self.food += amount * price
+
+    def add_drink(self, amount, price):
+        self.drink += amount * price
+
+    def total(self):
+        return "{}: {}, {}: {}, Total: {}".format(
+            self.food_name,
+            str(self.food),
+            self.drink_name,
+            str(self.drink),
+            str(self.drink + self.food)
+        )
+
+
+class JapaneseCook(AbstractCook):
+    def __init__(self):
+        super().__init__()
+        self.food_name = "Sushi"
+        self.drink_name = "Tea"
+
+
+class RussianCook(AbstractCook):
+    def __init__(self):
+        super().__init__()
+        self.food_name = "Dumplings"
+        self.drink_name = "Compote"
+
+
+class ItalianCook(AbstractCook):
+    def __init__(self):
+        super().__init__()
+        self.food_name = "Pizza"
+        self.drink_name = "Juice"
+
+
+if __name__ == '__main__':
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+
+    client_1 = JapaneseCook()
+    client_1.add_food(2, 30)
+    client_1.add_food(3, 15)
+    client_1.add_drink(2, 10)
+
+    client_2 = RussianCook()
+    client_2.add_food(1, 40)
+    client_2.add_food(2, 25)
+    client_2.add_drink(5, 20)
+
+    client_3 = ItalianCook()
+    client_3.add_food(2, 20)
+    client_3.add_food(2, 30)
+    client_3.add_drink(2, 10)
+
+    assert client_1.total() == "Sushi: 105, Tea: 20, Total: 125"
+    assert client_2.total() == "Dumplings: 90, Compote: 100, Total: 190"
+    assert client_3.total() == "Pizza: 100, Juice: 20, Total: 120"
+    print("Coding complete? Let's try tests!")
diff --git a/Dropbox/conversion-into-camelcase.py b/Dropbox/conversion-into-camelcase.py
new file mode 100644
index 0000000..e43901c
--- /dev/null
+++ b/Dropbox/conversion-into-camelcase.py
@@ -0,0 +1,21 @@
+def to_camel_case(name):
+    name = name[0].upper() + name[1:]
+    while True:
+        try:
+            index = name.index("_")
+            name = name[0:index] + name[index+1].upper() + name[index+2:]
+        except ValueError:
+            break
+    return name
+
+
+if __name__ == '__main__':
+    print("Example:")
+    print(to_camel_case('name'))
+
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+    assert to_camel_case("my_function_name") == "MyFunctionName"
+    assert to_camel_case("i_phone") == "IPhone"
+    assert to_camel_case("this_function_is_empty") == "ThisFunctionIsEmpty"
+    assert to_camel_case("name") == "Name"
+    print("Coding complete? Click 'Check' to earn cool rewards!")
diff --git a/Dropbox/the-most-frequent-weekdays.py b/Dropbox/the-most-frequent-weekdays.py
new file mode 100644
index 0000000..18c2329
--- /dev/null
+++ b/Dropbox/the-most-frequent-weekdays.py
@@ -0,0 +1,36 @@
+from datetime import date, timedelta
+
+
+def most_frequent_days(a):
+    week = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"]
+    days = {"Monday": 0, "Tuesday": 0, "Wednesday": 0, "Thursday": 0, "Friday": 0, "Saturday": 0, "Sunday": 0}
+    plus_a_day = timedelta(days=1)
+    first_date = date(a, 1, 1)
+    last_date = date(a, 12, 31)
+    while first_date <= last_date:
+        days[week[first_date.weekday()]] += 1
+        first_date += plus_a_day
+    return [day for day, count in days.items() if count == max(days.values())]
+
+
+if __name__ == '__main__':
+    print("Example:")
+    print(most_frequent_days(1084))
+
+    # These "asserts" are used for self-checking and not for an auto-testing
+    assert most_frequent_days(1084) == ['Tuesday', 'Wednesday']
+    assert most_frequent_days(1167) == ['Sunday']
+    assert most_frequent_days(1216) == ['Friday', 'Saturday']
+    assert most_frequent_days(1492) == ['Friday', 'Saturday']
+    assert most_frequent_days(1770) == ['Monday']
+    assert most_frequent_days(1785) == ['Saturday']
+    assert most_frequent_days(212) == ['Wednesday', 'Thursday']
+    assert most_frequent_days(1) == ['Monday']
+    assert most_frequent_days(2135) == ['Saturday']
+    assert most_frequent_days(3043) == ['Sunday']
+    assert most_frequent_days(2001) == ['Monday']
+    assert most_frequent_days(3150) == ['Sunday']
+    assert most_frequent_days(3230) == ['Tuesday']
+    assert most_frequent_days(328) == ['Monday', 'Sunday']
+    assert most_frequent_days(2016) == ['Friday', 'Saturday']
+    print("Coding complete? Click 'Check' to earn cool rewards!")
diff --git a/Dropbox/unlucky-days.py b/Dropbox/unlucky-days.py
new file mode 100644
index 0000000..461d237
--- /dev/null
+++ b/Dropbox/unlucky-days.py
@@ -0,0 +1,21 @@
+from datetime import date
+
+
+def checkio(year: int) -> int:
+    count = 0
+    for month in range(1, 13):
+        current_date = date(year, month, 13)
+        if current_date.weekday() == 4:
+            count += 1
+    return count
+
+
+if __name__ == '__main__':
+    print("Example:")
+    print(checkio(2015))
+
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+    assert checkio(2015) == 3, "First - 2015"
+    assert checkio(1986) == 1, "Second - 1986"
+    assert checkio(2689) == 2, "Third"
+    print("Coding complete? Click 'Check' to earn cool rewards!")
diff --git a/IceBase/the-healers.py b/IceBase/the-healers.py
new file mode 100644
index 0000000..5fc1c8a
--- /dev/null
+++ b/IceBase/the-healers.py
@@ -0,0 +1,189 @@
+# Taken from mission The Lancers
+
+# Taken from mission The Vampires
+# Taken from mission The Defenders
+# Taken from mission Army Battles
+# Taken from mission The Warriors
+
+
+class Warrior:
+    def __init__(self):
+        self.health = 50
+        self.attack = 5
+        self.is_alive = True
+        self.defense = 0
+        self.vampirism = 0
+        self.healing = 0
+
+    def hit(self, other_unit) -> bool:
+        hit_points = self.attack - other_unit.defense
+        hit_points = hit_points if hit_points > 0 else 0
+        other_unit.health -= hit_points
+        other_unit.is_alive = other_unit.health > 0
+
+        self.health += (hit_points * self.vampirism)
+        return other_unit.is_alive
+
+
+class Knight(Warrior):
+    def __init__(self):
+        super().__init__()
+        self.attack = 7
+
+
+class Defender(Warrior):
+    def __init__(self):
+        super().__init__()
+        self.health = 60
+        self.attack = 3
+        self.defense = 2
+
+
+class Vampire(Warrior):
+    def __init__(self):
+        super().__init__()
+        self.health = 40
+        self.attack = 4
+        self.vampirism = 0.5
+
+
+class Rookie(Warrior):
+    def __init__(self, *args, **kwargs):
+        super().__init__()
+        self.health = 50
+        self.attack = 1
+
+
+class Lancer(Warrior):
+    def __init__(self):
+        super().__init__()
+        self.attack = 6
+
+
+class Healer(Warrior):
+    def __init__(self):
+        super().__init__()
+        self.health = 60
+        self.attack = 0
+        self.healing = 2
+
+    def heal(self, unit: Warrior):
+        unit.health += self.healing
+
+
+def fight(unit_1, unit_2):
+    while unit_1.is_alive and unit_2.is_alive:
+        if not unit_1.hit(unit_2):
+            return True
+        if not unit_2.hit(unit_1):
+            return False
+
+
+class Army:
+    def __init__(self):
+        self.units = []
+
+    def add_units(self, unit_type, quantity):
+        for i in range(quantity):
+            self.units.append(unit_type())
+
+
+class Battle:
+    @staticmethod
+    def fight(army_1: Army, army_2: Army) -> bool:
+        while len(army_1.units) > 0 and len(army_2.units) > 0:
+            current_unit_1 = army_1.units[0]
+            current_unit_2 = army_2.units[0]
+            while current_unit_1.is_alive and current_unit_2.is_alive:
+                current_unit_1_attack = current_unit_1.hit(current_unit_2)
+                if len(army_1.units) > 1 and isinstance(army_1.units[1], Healer):
+                    current_unit_1.health += army_1.units[1].healing
+                if isinstance(current_unit_1, Lancer) and len(army_2.units) > 1:
+                    army_2.units[1].health -= current_unit_1.attack * 0.5
+                if not current_unit_1_attack:
+                    army_2.units.pop(0)
+                    break
+                current_unit_2_attack = current_unit_2.hit(current_unit_1)
+                if len(army_2.units) > 1 and isinstance(army_2.units[1], Healer):
+                    current_unit_2.health += army_2.units[1].healing
+                if isinstance(current_unit_2, Lancer) and len(army_1.units) > 1:
+                    army_1.units[1].health -= current_unit_2.attack * 0.5
+                if not current_unit_2_attack:
+                    army_1.units.pop(0)
+                    break
+        return len(army_1.units) > 0
+
+
+if __name__ == '__main__':
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+
+    # fight tests
+    chuck = Warrior()
+    bruce = Warrior()
+    carl = Knight()
+    dave = Warrior()
+    mark = Warrior()
+    bob = Defender()
+    mike = Knight()
+    rog = Warrior()
+    lancelot = Defender()
+    eric = Vampire()
+    adam = Vampire()
+    richard = Defender()
+    ogre = Warrior()
+    freelancer = Lancer()
+    vampire = Vampire()
+    priest = Healer()
+
+    assert fight(chuck, bruce) == True
+    assert fight(dave, carl) == False
+    assert chuck.is_alive == True
+    assert bruce.is_alive == False
+    assert carl.is_alive == True
+    assert dave.is_alive == False
+    assert fight(carl, mark) == False
+    assert carl.is_alive == False
+    assert fight(bob, mike) == False
+    assert fight(lancelot, rog) == True
+    assert fight(eric, richard) == False
+    assert fight(ogre, adam) == True
+    assert fight(freelancer, vampire) == True
+    assert freelancer.is_alive == True
+    assert freelancer.health == 14
+    priest.heal(freelancer)
+    assert freelancer.health == 16
+
+    # battle tests
+    my_army = Army()
+    my_army.add_units(Defender, 2)
+    my_army.add_units(Healer, 1)
+    my_army.add_units(Vampire, 2)
+    my_army.add_units(Lancer, 2)
+    my_army.add_units(Healer, 1)
+    my_army.add_units(Warrior, 1)
+
+    enemy_army = Army()
+    enemy_army.add_units(Warrior, 2)
+    enemy_army.add_units(Lancer, 4)
+    enemy_army.add_units(Healer, 1)
+    enemy_army.add_units(Defender, 2)
+    enemy_army.add_units(Vampire, 3)
+    enemy_army.add_units(Healer, 1)
+
+    army_3 = Army()
+    army_3.add_units(Warrior, 1)
+    army_3.add_units(Lancer, 1)
+    army_3.add_units(Healer, 1)
+    army_3.add_units(Defender, 2)
+
+    army_4 = Army()
+    army_4.add_units(Vampire, 3)
+    army_4.add_units(Warrior, 1)
+    army_4.add_units(Healer, 1)
+    army_4.add_units(Lancer, 2)
+
+    battle = Battle()
+
+    assert battle.fight(my_army, enemy_army) == False
+    assert battle.fight(army_3, army_4) == True
+    print("Coding complete? Let's try tests!")
\ No newline at end of file
diff --git a/OReilly/remove-accents.py b/OReilly/remove-accents.py
new file mode 100644
index 0000000..aad5ced
--- /dev/null
+++ b/OReilly/remove-accents.py
@@ -0,0 +1,12 @@
+import unicodedata
+
+
+def checkio(in_string):
+    """remove accents"""
+    return ''.join(c for c in unicodedata.normalize('NFD', in_string) if unicodedata.category(c) != 'Mn')
+
+
+if __name__ == '__main__':
+    assert checkio(u"préfèrent") == u"preferent"
+    assert checkio(u"loài trăn lớn") == u"loai tran lon"
+    print('Done')
diff --git a/PyconTW/simplify-unix-path.py b/PyconTW/simplify-unix-path.py
new file mode 100644
index 0000000..9a66fa2
--- /dev/null
+++ b/PyconTW/simplify-unix-path.py
@@ -0,0 +1,59 @@
+def simplify_path(path):
+    """
+        simplifying a given path
+    """
+    folders = path.split("/")
+    new_folders = []
+    for folder in folders:
+        if folder == "" or folder == ".":
+            continue
+        elif folder == "..":
+            try:
+                if new_folders[-1] != "..":
+                    new_folders.pop()
+                else:
+                    new_folders.append("..")
+            except IndexError:
+                if path[0] == "/":
+                    print("you can't go deeper than root folder")
+                else:
+                    new_folders.append("..")
+        else:
+            new_folders.append(folder)
+    new_folders = "/".join(new_folders)
+    if not path[0].isalpha() and path[0] != ".":
+        new_folders = path[0] + new_folders
+    if len(new_folders) == 0:
+        new_folders = "."
+    print(new_folders)
+    return new_folders
+
+
+if __name__ == '__main__':
+    # These "asserts" using only for self-checking and not necessary for auto-testing
+
+    # last slash is not important
+    assert simplify_path('/a/') == '/a'
+
+    # double slash can be united in one
+    assert simplify_path('/a//b/c') == '/a/b/c'
+
+    # double dot - go to previous folder
+    assert simplify_path('dir/fol/../no') == 'dir/no'
+    assert simplify_path('dir/fol/../../no') == 'no'
+
+    # one dot means current dir
+    assert simplify_path('/a/b/./ci') == '/a/b/ci'
+    assert simplify_path('vi/..') == '.'
+    assert simplify_path('./.') == '.'
+
+    # you can't go deeper than root folder
+    assert simplify_path('/for/../..') == '/'
+    assert simplify_path('/for/../../no/..') == '/'
+
+    # not all double-dots can be simplyfied in related path
+    assert simplify_path('for/../..') == '..'
+    assert simplify_path('../foo') == '../foo'
+
+    assert simplify_path(".././..") == "../.."
+    print('Simply enough! Let\'s check it now!!')