func_code_string: #include <bits/stdc++.h>   int cut;   int q[100005] = {0};   int totalnode, totaledge, i, j, k, l, a, b, t1, t2;   int c(int q) {     if (q == 2) {       return cut;     } else if (q == cut) {       return 2;     } else       return q;   }   int main() {     for (i = 0; i < 100005; i++) q[i] = i;     scanf( %d %d %d , &totalnode, &totaledge, &cut);     q[cut] = 2;     q[2] = cut;     if (totaledge >= totalnode - 1 &&         (totalnode - 1) * (totalnode - 2) / 2 + 1 >= totaledge) {       for (i = 1; i <= totalnode - 1; i++) {         printf( %d %d n , q[i], q[i + 1]);         totaledge--;       }       for (i = 2; i <= totalnode && totaledge > 0; i++) {         for (j = i + 2; j <= totalnode && totaledge > 0; j++) {           printf( %d %d n , q[i], q[j]);           totaledge--;         }       }     } else {       printf( -1 );     }     return 0;   }   