80pts

//Source Code
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#include <queue>
#include <map>
#include <cctype>
#include <set>
#include <stack>

//using namespace std;

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;

constexpr i64 N = 1e6 + 10;
constexpr i64 INF = 1e9 + 10;
constexpr i64 MOD = 998244353;
constexpr i64 P = 1e9 + 7;

i64 ans;
int _;
int ask;

inline void solve(){
	i64 l = 1 , r = INF;
	while (l <= r) {
		i64 mid = l + r >> 1;
		std :: cout << mid << std :: endl;		
		int o;
		std :: cin >> o;
		if (o == 0) {
			return ;
		} if (o == -1) l = mid + 1;
		if (o == 1) r = mid - 1; 
	}
	return ;
}

signed main(){
	std :: ios :: sync_with_stdio(false);
	std :: cin.tie(0) , std :: cout.tie(0);
	//std :: cin >> _;
	_ = 1;
	while(_ --> 0) solve();
	return (0 - 0);
}

/*

*/