#include<iostream>
#include<cassert>
using namespace std;
#define rep(i,n) for(int i=0;i<(n);++i)

int main(){
	int now=1e9;
	while(now){
		cout<<now<<endl;
		int t;
		cin>>t;
		assert(t!=-1);
		if(t==1) break;
		now/=2;
	}
}