func_code_string: #include<iostream>   using namespace std;      int query(int a, int b) {    cout <<  ?   << a <<     << b << endl;    cout.flush();    int ret;    cin >> ret;    return ret;   }      int main() {    int n;    cin >> n;    int lt = 1, rt = n;    int sec = query(1, n);    while (rt - lt > 0) {     int mid;     if (rt + lt <= 2 * sec) {      mid = (rt + lt + 1) / 2;      if (mid == n) {       rt = n - 1;       break;      }      if (query(mid, n) == sec) lt = mid;      else rt = mid - 1;     }     if (rt+lt > 2*sec) {      mid = (rt + lt) / 2;      if (mid == 1) {       lt = 2;       break;      }      if (query(1, mid) == sec) rt = mid;      else lt = mid + 1;     }    }    cout <<  !   << lt << endl;    cout.flush();   }