func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     vector<int> ans(n);     int a1, a2, a3;     cout <<  ? 1 2  << endl;     fflush(stdout);     cin >> a1;     cout <<  ? 1 3  << endl;     fflush(stdout);     cin >> a2;     cout <<  ? 2 3  << endl;     fflush(stdout);     cin >> a3;     int t = (a1 + a2 - a3) / 2;     ans[0] = t;     ans[2] = a2 - t;     ans[1] = a3 - ans[2];     for (int i = 3; i < n; i++) {       int now = 0;       cout <<  ? 1   << i + 1 << endl;       fflush(stdout);       cin >> now;       ans[i] = now - t;     }     cout <<  !  ;     for (int i = 0; i < n; i++) {       cout << ans[i] <<    ;     }     return 0;   }   