diff --git a/TangDou/Topic/HuanGenDp/P6419.cpp b/TangDou/Topic/HuanGenDp/P6419.cpp
index 30745dd..f9faccc 100644
--- a/TangDou/Topic/HuanGenDp/P6419.cpp
+++ b/TangDou/Topic/HuanGenDp/P6419.cpp
@@ -3,7 +3,7 @@ using namespace std;
 const int N = 500010, M = N << 1;
 #define int long long
 
-int n, K;
+int n, m;
 
 // 链式前向星
 int e[M], h[N], idx, w[M], ne[M];
@@ -14,9 +14,9 @@ void add(int a, int b, int c = 0) {
 int pos[N];
 int sz[N], g[N], f[N];
 int len[N], id[N], slen[N];
+
 void dfs1(int u, int fa) {
     if (pos[u]) sz[u] = 1;
-
     for (int i = h[u]; ~i; i = ne[i]) {
         int v = e[i];
         if (v == fa) continue;
@@ -32,13 +32,14 @@ void dfs1(int u, int fa) {
         sz[u] += sz[v];
     }
 }
+
 void dfs2(int u, int fa) {
     for (int i = h[u]; ~i; i = ne[i]) {
         int v = e[i];
         if (v == fa) continue;
         if (!sz[v])
             f[v] = f[u] + 2 * w[i], len[v] = len[u] + w[i];
-        else if (K - sz[v]) {
+        else if (m - sz[v]) {
             f[v] = f[u];
             if (id[u] != v && len[v] < len[u] + w[i])
                 slen[v] = len[v], len[v] = len[u] + w[i], id[v] = u;
@@ -57,13 +58,13 @@ signed main() {
     // 初始化链式前向星
     memset(h, -1, sizeof h);
 
-    cin >> n >> K;
+    cin >> n >> m;
     for (int i = 1; i < n; i++) {
         int a, b, c;
         cin >> a >> b >> c;
         add(a, b, c), add(b, a, c);
     }
-    for (int i = 1; i <= K; i++) {
+    for (int i = 1; i <= m; i++) {
         int x;
         cin >> x;
         pos[x] = 1;