func_code_string: #include <bits/stdc++.h>   using namespace std;   long long KuriBija[1005];   long long A;   long long Cik, lol;   int main() {     cin >> Cik >> lol;     for (long long i = 0; i < lol; i++) {       cin >> A;       KuriBija[A] = 1;       cin >> A;       KuriBija[A] = 1;     }     lol = 1;     while (KuriBija[lol] != 0) {       lol++;     }     cout << Cik - 1 << endl;     for (long long i = 0; i < Cik; i++) {       if (i + 1 != lol) {         cout << lol <<     << i + 1 << endl;       }     }   }   