Uneven Sand

    1#include <bits/stdc++.h>
    2 
    3using namespace std;
    4 
    5int main(){
    6    ios::sync_with_stdio(0);
    7    cin.tie(0);
    8    long long hi = 2 * 1e9, low = 1;
    9    while(low <= hi){
    10        long long mid = low + (hi - low) / 2;
    11        cout << mid << endl;
    12        string inst;
    13        cin >> inst;
    14        if(inst == "FLOATS"){
    15            hi = mid - 1;
    16        }
    17        else if (inst == "SINKS"){
    18            low = mid + 1;
    19        } else {
    20            exit(0);
    21        }
    22    }
    23    return 0;
    24}