#include<bits/stdc++.h>
using namespace std;
#define int long long
const int inf = 2000000000000000000;
signed main(){
    int x=500000000;
    for(int i=0;i<30;i++){
        cout<<x<<"\n";
        int ret;cin>>ret;
        if(ret==1)return(0);
        x/=2;
    }
}