func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 2e5 + 100;   const long long inf = 1e18;   vector<int> g[maxn];   bool visit[maxn];   int cnt = 0;   void dfs(int u) {     cnt = 0;     queue<int> q;     q.push(u);     visit[u] = true;     cnt++;     while (!q.empty()) {       int u = q.front();       q.pop();       for (auto v : g[u])         if (visit[v] == false) {           q.push(v);           visit[v] = true;           cnt++;         }     }   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     int n, m;     cin >> n >> m;     vector<int> st;     int u, v;     memset(visit, false, sizeof visit);     for (int i = 1; i <= m; i++) {       cin >> u >> v;       g[u].push_back(v);       g[v].push_back(u);       st.push_back(u);       st.push_back(v);     }     int ans = 0;     for (auto v : st) {       if (visit[v] == false) {         dfs(v);         ans += (cnt - 1);         cnt = 0;       }     }     cout << (m - ans) << endl;     return 0;   }   