func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int n, m, a[4005], b[4005];     bitset<4005> adj[4005];     cin >> n >> m;     vector<int> tam(n + 1);     for (int i = 0; i < m; i++) {       cin >> a[i] >> b[i];       adj[a[i]][b[i]] = 1;       adj[b[i]][a[i]] = 1;       tam[a[i]]++;       tam[b[i]]++;     }     int res = 1e9;     for (int i = 0; i < m; i++) {       for (int j = i + 1; j < m; j++) {         vector<int> v = {a[i], b[i], a[j], b[j]};         sort(v.begin(), v.end());         v.erase(unique(v.begin(), v.end()), v.end());         if (v.size() != 3) continue;         if (adj[v[0]][v[1]] && adj[v[1]][v[2]] && adj[v[2]][v[0]]) {           res = min(res, tam[v[0]] + tam[v[1]] + tam[v[2]] - 6);         }       }     }     if (res == 1e9)       cout << -1 <<   n ;     else       cout << res <<   n ;     return 0;   }   