func_code_string: #include <bits/stdc++.h>   using namespace std;   constexpr long long maxn = 2e5 + 5, inf = 0x3f3f3f3f;   vector<long long> e[maxn];   long long n, m, k, c[maxn], ans;   void dfs(long long u, long long fa) {     for (auto v : e[u]) {       if (v == fa) continue;       dfs(v, u);       c[u] += c[v];       ans += min(c[v], k - c[v]);     }   }   signed main() {     cin >> n >> k;     k *= 2;     for (long long i = 1; i <= k; i++) {       long long x;       cin >> x;       c[x] = 1;     }     for (long long i = 1; i < n; i++) {       long long u, v;       cin >> u >> v;       e[u].push_back(v);       e[v].push_back(u);     }     dfs(1, 1);     cout << ans;   }   