diff --git a/knotknowledge.py b/knotknowledge.py
new file mode 100644
index 0000000..197db48
--- /dev/null
+++ b/knotknowledge.py
@@ -0,0 +1,4 @@
+_ = input()
+knots = set(map(int, input().split()))
+learnedknots = set(map(int, input().split()))
+print(list(knots.difference(learnedknots))[0])