#include <iostream>
#include <map>
#include <set>
#include <queue>
#include <cmath>
#include <vector>
#include <string>
#include <algorithm>
#include <functional>
using namespace std;
#pragma warning (disable: 4996)

int main() {
	int cl = 1, cr = 1005, cm, maxn = 0;
	for (int i = 0; i < 12; i++) {
		cm = (cl + cr) / 2;
		cout << "? " << cm + 0 << endl; string t1; cin >> t1;
		cout << "? " << cm + 1 << endl; string t2; cin >> t2;
		if (t1 == "safe") maxn = max(maxn, cm + 0);
		if (t2 == "safe") maxn = max(maxn, cm + 1);
		if (t1 == "out" && t2 == "out") { cr = cm; }
		else { cl = cm; }
	}
	cout << "! " << maxn << endl;
	return 0;
}