func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int N;     cin >> N;     int black = 0, white = 1000000001;     cout << 0 <<     << 0 << endl;     cout << flush;     string S;     cin >> S;     if (S ==  white ) swap(white, black);     for (int i = 1; i < N; i++) {       int mid = (white + black) / 2;       cout << mid <<     << 0 << endl;       cout << flush;       cin >> S;       if (S ==  black ) {         black = mid;       } else {         white = mid;       }     }     if (black + 1 < white || white + 1 < black)       cout << (black + white) / 2 <<     << 1 <<     << (black + white) / 2 <<                << 2 << endl;     else {       if (black < white) {         if (black > 0)           cout << black <<     << 1 <<     << black - 1 <<     << 3 << endl;         else           cout << black + 1 <<     << 1 <<     << black + 2 <<     << 3 << endl;       } else {         if (white > 0)           cout << white <<     << 1 <<     << white - 1 <<     << 3 << endl;         else           cout << white + 1 <<     << 1 <<     << white + 2 <<     << 3 << endl;       }     }     return 0;   }   