#include<iostream>
#include<vector>
#include<set>
#include<map>
#include<list>
#include<stack>
#include<queue>
#include<bitset>
#include<array>
#include<algorithm>
#include<cstdio>
#include<string>
#include<cstdlib>
#include<numeric>
#define D int
#define U unsigned
using namespace std;
D n, m, a, b, d, e;
char c;
bool g, h;
string s;
D threex[3] = { 0,1,1 };
D threey[3] = { 1,1,0 };
D ans;
D p[102][102],q[102][102];
int main() {
	D i, j, k;
	D t, u;
	cout << "? 100" << endl;
	cin >> t;
	if (t == 0) {
		cout << "! 100" << endl;
	}
	else if (t==-1) {
		for (i = 1; i < 100; i++) {
			cout << "? 0" << endl;
			cin >> t;
			if (t == 0)
				break;
		}
		cout << "! " << i << endl;
	}
	else {
		u = 0;
		for (i = 29; i >= 0; i--) {
			u += 1 << i;
			cout << "? " << u - (30 - i) << endl;
			cin >> t;
			if (t == 0) {
				cout << "! " << u << endl;
				break;
			}
			else if (t == -1) {
				u -= 1 << i;
			}
		}
	}
}