diff --git a/TangDou/Topic/HuanGenDp/CF1406.cpp b/TangDou/Topic/HuanGenDp/CF1406C.cpp
similarity index 92%
rename from TangDou/Topic/HuanGenDp/CF1406.cpp
rename to TangDou/Topic/HuanGenDp/CF1406C.cpp
index 6560d67..7774d1b 100644
--- a/TangDou/Topic/HuanGenDp/CF1406.cpp
+++ b/TangDou/Topic/HuanGenDp/CF1406C.cpp
@@ -31,8 +31,16 @@ void dfs(int u, int fa) {
     son[u] = max(son[u], n - sz[u]);
     if ((son[u] << 1) <= n) r2 = r1, r1 = u;
 }
-
+/*
+1 2
+1 2
+1 3
+2 3
+*/
 signed main() {
+#ifndef ONLINE_JUDGE
+    freopen("CF1406C.in", "r", stdin);
+#endif
     int T;
     cin >> T;
     while (T--) {
diff --git a/TangDou/Topic/HuanGenDp/CF1406C.in b/TangDou/Topic/HuanGenDp/CF1406C.in
new file mode 100644
index 0000000..a0de3a0
--- /dev/null
+++ b/TangDou/Topic/HuanGenDp/CF1406C.in
@@ -0,0 +1,12 @@
+2
+5
+1 2
+1 3
+2 4
+2 5
+6
+1 2
+1 3
+1 4
+2 5
+2 6