#include <bits/stdc++.h>
using namespace std;

char ans;
void ask(int x, int y) {
    cout << "? " << x << " " << y << endl;
    cin >> ans;
}

int main() {
    string s;
    cin >> s;
    while (s != "end") {
		int curp = 1, prp = 0;

        ask(0, curp);
		while (ans == 'y') {
			prp = curp;
			curp *= 2;
			ask(prp, curp);
		}

		int L = prp, R = curp;
		while (R - L > 1) {
			int MID = L + R >> 1;

			ask(L, MID);

			if (ans == 'x')
				R = MID;
			else
				L = MID;
		}

		cout << "! " << R << endl;

		cin >> s;
	}
}