#include <iostream>

using namespace std;
int bins(int x,int min,int max)
{
    int v;
    int pivot=(min+max)/2;
    cout <<x<<" "<< pivot<< "\n";
    cout.flush();
    cin >>v;
    if(v==0) return 0;
    if(max-min==1) return -1;
    if(v<0) return bins(x,pivot,max);
    return bins(x,min,pivot);
}

int main()
{
    int i=0;
    while(bins(i,0,199)!=0){i++;}
    return 0;
}