diff --git a/day06/part1.py b/day06/part1.py
index f5a26f8..3b6e1b3 100644
--- a/day06/part1.py
+++ b/day06/part1.py
@@ -5,7 +5,6 @@ counter = Counter(map(int, [x for x in open("input.txt")][0].split(',')))
 counter = [counter.get(idx, 0) for idx in range(0, 9)]
 
 for day in range(80):
-    counter = counter[1:] + counter[:1]
-    counter[6] += counter[-1]
+    counter[(day+7) % 9] += counter[day % 9]
 
 print(sum(counter))
diff --git a/day06/part2.py b/day06/part2.py
index c63ebe9..eab6a06 100644
--- a/day06/part2.py
+++ b/day06/part2.py
@@ -5,7 +5,6 @@ counter = Counter(map(int, [x for x in open("input.txt")][0].split(',')))
 counter = [counter.get(idx, 0) for idx in range(0, 9)]
 
 for day in range(256):
-    counter = counter[1:] + counter[:1]
-    counter[6] += counter[-1]
+    counter[(day+7) % 9] += counter[day % 9]
 
 print(sum(counter))