func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int i, j, n, a[5002], b, c, d;     cin >> n;     cout <<  ?  <<     << 1 <<     << 2 << endl;     fflush(stdout);     cin >> b;     cout <<  ?  <<     << 2 <<     << 3 << endl;     fflush(stdout);     cin >> c;     cout <<  ?  <<     << 1 <<     << 3 << endl;     fflush(stdout);     cin >> d;     a[1] = (b + d - c) / 2;     a[2] = b - a[1];     a[3] = d - a[1];     for (i = 4; i <= n; i++) {       cout <<  ?  <<     << 1 <<     << i << endl;       fflush(stdout);       cin >> b;       a[i] = b - a[1];     }     cout <<  !  <<    ;     for (i = 1; i <= n; i++) cout << a[i] <<    ;     return 0;   }   