#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

	int now = 1000000000;
	while(true){
		now = (now+1)/2; 
		cout << now << endl;
		int x; cin >> x;
		if(x == 1) break;
	}
}