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

int main() {
    int r = 500000000;
    for (int i = 0;i < 30;i++) {
        cout << r << endl;
        int a = 0;
        cin >> a;
        if (a) {
            return 0;
        } else {
            r /= 2;
        }
    }
}