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

int main(){
    string str;
    cin >> str;
    cout << "? aa" << endl;
    while(1){
        string a,b;
        cin >> a >> b;
        if(a == "!"){
            return 0;
        }
        cout  << "? " << b[1] << 'a' << endl;
    }
    
}