func_code_string: #include <bits/stdc++.h>   using namespace std;   int p1[10][13], p2[10][13];   bool fl = false;   int c1[10], c2[10];   int len, n, m;   int sum = 0, ans;   int main() {     memset(c1, 0, sizeof(c1));     memset(c2, 0, sizeof(c2));     memset(p1, -1, sizeof(p1));     memset(p2, -1, sizeof(p2));     scanf( %d%d , &n, &m);     for (int i = 0; i < n; i++) {       int a, b;       scanf( %d%d , &a, &b);       p1[a][c1[a]++] = b;       p1[b][c1[b]++] = a;     }     for (int i = 0; i < m; i++) {       int a, b;       scanf( %d%d , &a, &b);       p2[a][c2[a]++] = b;       p2[b][c2[b]++] = a;     }     for (int i = 1; i <= 9; i++) {       if (p1[i][0] == -1 || p2[i][0] == -1) {         continue;       }       for (int j = 0; j < c1[i]; j++) {         for (int k = 0; k < c2[i]; k++) {           if (p1[i][j] == p2[i][k]) {             continue;           }           for (int t = 0; t < c2[p1[i][j]]; t++) {             if (p2[p1[i][j]][t] != -1 && p2[p1[i][j]][t] != i) {               fl = true;               break;             }           }           for (int t = 0; t < c1[p2[i][k]]; t++) {             if (p1[p2[i][k]][t] != -1 && p1[p2[i][k]][t] != i) {               fl = true;               break;             }           }           if (fl) break;           if (i != ans) sum++;           ans = i;         }         if (fl) break;       }     }     if (fl) {       printf( -1 n );     } else {       if (sum == 1) printf( %d n , ans);       if (sum > 1) printf( 0 n );     }     return 0;   }   