diff --git a/day_23/part_1.php b/day_23/part_1.php
new file mode 100644
index 0000000..ac83d3e
--- /dev/null
+++ b/day_23/part_1.php
@@ -0,0 +1,60 @@
+<?php
+
+$cups = array_map('intval', str_split(file_get_contents('input.txt')));
+$min = min($cups);
+$max = max($cups);
+
+$current_index = 0;
+
+for ($i = 0; $i < 100; $i++) {
+    $current_cup = $cups[$current_index];
+
+    $pickups = array_splice($cups, $current_index + 1, 3);
+
+    while (count($pickups) < 3) {
+        $pickups[] = array_shift($cups);
+    }
+
+    $destination = $current_cup;
+    do {
+        $destination--;
+        if ($destination < $min) {
+            $destination = $max;
+        }
+    } while (in_array($destination, $pickups, true));
+
+    $destination_index = array_search($destination, $cups, true);
+
+    array_splice($cups, $destination_index + 1, null, $pickups);
+    $cups = array_values($cups);
+
+    // replace current index at its position
+    if ($cups[$current_index] !== $current_cup) {
+        $diff = array_search($current_cup, $cups, true) - $current_index;
+        for ($j = 0; $j < abs($diff); $j++) {
+            $cups[] = array_shift($cups);
+        }
+    }
+
+    echo sprintf('move %u : %s%s', $i+1, implode(' ', $cups), "\n");
+
+    $current_index++;
+    if ($current_index >= count($cups)) {
+        $current_index = 0;
+    }
+}
+
+// moves done, now count from 1
+$index_1 = array_search(1, $cups, true);
+$final_labels = '';
+$current_index = $index_1 + 1;
+for ($i = 1, $l = count($cups); $i < $l; $i++) {
+    if ($current_index >= $l) {
+        $current_index = 0;
+    }
+    $final_labels .= $cups[$current_index];
+    $current_index++;
+}
+
+echo $final_labels;
+