func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, x, a, b, c = 0;     cin >> n >> x;     while (n--) {       cin >> a >> b;       if (x == a || x == b || x == 7 - a || x == 7 - b) c++;       x = 7 - x;     }     if (c > 0)       cout <<  NO  << endl;     else       cout <<  YES  << endl;     return 0;   }   