//1と5*10^8以外乱択(嘘解法)
//テストケースが弱いと通る
#include <iostream>
#include <algorithm>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;

int randInt(int L, int R){
  return rand() % (R - L + 1) + L;
}

int main(){
  vector<int> v;
  v.push_back(1);
  v.push_back(5*1e8);
  srand((unsigned)time(NULL));
  for(int i = 1; i <= 28; i++){
    v.push_back(randInt(2, 5*1e8 - 1));
  }
  sort(v.begin(), v.end());
  /*for(int i = 0; i < 30; i++) cout << v[i] << " ";
  cout << endl;*/
  for(int i = (int)v.size() - 1; i >= 0; i--){
    cout << v[i] << endl;
    cout.flush();
    int ret;
    cin >> ret;
    if(ret == 0) continue;
    else break;
  }
  return 0;
}