func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = 0x3f3f3f3f;   const int N = 2e5 + 10;   char s[3][N];   int main() {     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       for (int i = 1; i <= 2; i++)         for (int j = 1; j <= n; j++) {           cin >> s[i][j];           if (s[i][j] ==  1  || s[i][j] ==  2 )             s[i][j] =  1 ;           else             s[i][j] =  2 ;         }       int flag = 0, x = 1, y = 1;       for (int i = 1; i <= n; i++) {         if (s[y][i] ==  1 ) {           x++;         } else if (s[y][i] ==  2 ) {           if (y == 1 && s[y + 1][i] ==  2 ) {             y++;             x++;           } else if (y == 2 && s[y - 1][i] ==  2 ) {             y--;             x++;           } else {             flag = 1;             break;           }         }       }       if (flag)         cout <<  NO  << endl;       else if (x == n + 1 && y == 2)         cout <<  YES  << endl;       else         cout <<  NO  << endl;     }     return 0;   }   