func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 100005;   int main() {     int n, m, t;     cin >> n >> m >> t;     int total = (n - 2) * (n - 1) / 2 + 1;     if (total >= m && m >= n - 1) {       m = m - n + 1;       int cant = 0;       if (t != 1)         cant = 1;       else         cant = n;       printf( %d %d n , t, cant);       for (int i = 1; i < n; i++) {         if (i != cant && i + 1 != cant) printf( %d %d n , i, i + 1);       }       for (int i = 1; i <= n && m; i++) {         if (t - i == 1 || i - t == 1 || t == i || i == cant) continue;         printf( %d %d n , i, t);         m--;       }       for (int i = 1; i <= n && m; i++) {         if (i == t || i == cant) continue;         for (int j = i + 2; j <= n && m; j++) {           if (j == t || j == cant) continue;           printf( %d %d n , i, j);           m--;         }       }     } else       puts( -1 );     return 0;   }   