func_code_string: #include <bits/stdc++.h>   using namespace std;   bool ask(int a, int b, int c, int d) {     cout <<  ?   << a <<     << b <<     << c <<     << d << endl;     fflush(stdout);     string response;     cin >> response;     if (response ==  BAD ) {       exit(0);     } else if (response ==  YES )       return true;     else       return false;   }   int main() {     int n;     cin >> n;     int x = 1, y = 1;     string ans1 =   , ans2 =   ;     for (int i = 0; i < n - 1; ++i) {       if (ask(x + 1, y, n, n)) {         x++;         ans1.push_back( D );       } else {         y++;         ans1.push_back( R );       }     }     x = n, y = n;     for (int i = 0; i < n - 1; ++i) {       if (ask(1, 1, x, y - 1)) {         y--;         ans2.push_back( R );       } else {         x--;         ans2.push_back( D );       }     }     reverse((ans2).begin(), (ans2).end());     string finalans = ans1 + ans2;     cout <<  !   << finalans << endl;     fflush(stdout);     return 0;   }   