#include <bits/stdc++.h>

using namespace std;

int main() {
    int x = 1e9;
    while (true) {
        cout << x << endl;
        int r;
        cin >> r;
        if (r == 1 || r == -1) {
            return 0;
        } else if (r == 0) {
            x /= 2;
        }
    }
    return 0;
}