diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -35,7 +35,7 @@
             for v in adj[r]:
                 if v == p:
                     continue
-                t = [0] + dfs(v, r)
+                t = [1] + dfs(v, r)
                 d = comb(t, d)
             return d
 
