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

#define rep(i, n) for( int i = 0; i < n; i++ )
using ll = long long;

int main() {
	char c;
	cin >> c;
	set<char> st;
	cout << "? " << c << c << endl;
	st.insert(c);
	while(1) {
		string t;
		cin >> t;
		if(t[0] == '!') break;
		st.insert(t[3]);
		rep(i, 26) {
			char cc = (char(i + 'a'));
			if(st.count(cc) == 0) {
				cout << "? " << cc << c << endl;
				st.insert(cc);
				break;
			}
		}
	}
}