#include <iostream>
#include <cstdio>

using namespace std;

int main() {

	int minus = 0;
	int ret;
	cout << "? 64" << endl;
	cin >> ret;
	minus++;

	if (ret == 0) {
		cout << "? 64" << endl;
		return 0;
	}

	int n_bit = ret == 1 ? 31 : 6;
	int ans = 1 << n_bit;
	ans--;
	for (int i = n_bit - 1; i >= 0; i--) {
		int tmp = ans - (1 << i);
		cout << "? " << tmp - minus << endl;
		cin >> ret;
		minus++;
		if (ret == 0) {
			ans = tmp;
			break;
		} else if (ret < 0) {
			ans = tmp;
		}
	}
	cout << "! " << ans << endl;
}