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

int cnt;

int main() {
    int l = 1;
    int r = 1000000000;
    int ans = 0;
    int x;
    cnt = 0;
    while (cnt <= 100) {
        cnt++;
        ans = (l + r) >> 1;
        printf("%d\n", ans);
        fflush(stdout);
        scanf("%d", &x);
        if (x == 0) {
            break;

        } else {
            if (x == 1) {
                r = ans - 1;
            } else {
                l = ans + 1;
            }
        }
    }

    return 0;
}