#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)s; i < (int)e; ++i)
#define all(a) (a).begin(), (a).end()

int main() {
    char a;
    cin >> a;
    
    char prev = a;
    
    while (true) {
        cout << "? " << prev << a << endl;
        
        string type, S;
        cin >> type >> S;
        
        if (type == "!") return 0;
        else {
            prev = S[1];
        }
    }
}