func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, ans, u, v, i, root_u, root_v, arr[100001], len[100001], c[100001],       k;   vector<pair<long long, long long> > in;   long long find(long long x) {     if (arr[x] == x) return x;     return arr[x] = find(arr[x]);   }   int main() {     cin >> n >> k;     for (i = 1; i <= n; i++) arr[i] = i, len[i] = 1;     for (i = 0; i < k; i++) {       cin >> u >> v;       root_u = find(u);       root_v = find(v);       if (root_u != root_v) arr[root_u] = root_v, len[root_v] += len[root_u];       c[u]++;     }     for (i = 1; i <= n; i++)       if (arr[i] != i) c[find(i)] += c[i];     for (i = 1; i <= n; i++)       if (arr[i] == i) ans += (c[i] - len[i] + 1);     cout << ans;     return 0;   }   