#include <bits/stdc++.h>
#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define REP(i, n) for (ll i = 0; i < (n); i++)
#define ALL(a) (a).begin(), (a).end()
using namespace std;
using ll = long long;

int main() {
    ll x = 1e9;


    while (true) {
        cout << x << endl;
        ll input1;
        cin >> input1;

        if (input1 == -1) {
            return 0;
        }

        if (input1 == 0) {
            x /= 2;
            continue;
        }
        else if (input1 == 1) {
            return 0;
        }
    }

    return 0;
}