/* -*- coding: utf-8 -*-
 *
 * 3011.cc:  No.3011 縺ゅ€∽ｿｺ縺薙＞縺､縺ｮ蠖ｹ繧・ｊ縺溘＞! - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_N = 1000000000;

/* main */

int main() {
  int x = MAX_N;

  for (;;) {
    x = (x + 1) / 2;
    printf("%d\n", x); fflush(stdout);
    
    int r;
    scanf("%d", &r);
    if (r != 0) break;
  }

  for (int i = 0; i < 1000000000; i++);
  return 0;
}