func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, m;     cin >> n >> m;     vector<set<int> > g(n + 1);     map<int, int> co;     for (int i = 0; i < m; i++) {       int n1, n2;       cin >> n1 >> n2;       g[n1].insert(n2);       g[n2].insert(n1);       co[n1]++;       co[n2]++;     }     int minn = 1000000000;     for (int i = 1; i <= n; i++) {       set<int>::iterator iter;       for (iter = g[i].begin(); iter != g[i].end(); iter++) {         set<int>::iterator iter2;         for (iter2 = g[*iter].begin(); iter2 != g[*iter].end(); iter2++) {           if (*iter2 == i) continue;           if (g[*iter2].count(i)) {             minn = min(minn, co[*iter] + co[*iter2] + co[i] - 6);           }         }       }     }     if (minn == 1000000000)       cout << -1 << endl;     else       cout << minn << endl;     return 0;   }   