#include <bits/stdc++.h>

using namespace std;
using ll = long long;

void query(string &S){
    cout << "? " << S << endl;
}
void answer(string &T){
    cout << "! " << T << endl;
}

int main(){
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);

    int N, M;
    cin >> N;
    string S=string(N, 'a');
    for (int i=0; i<N; i++){
        int mi=1e9, mx=0;
        char c='.';
        for (int j=0; j<25; j++){
            S[i] = char('a'+j);
            query(S);
            cin >> M;
            if (M > mx){
                mx = M;
                c = char('a'+j);
            }
            mi = min(mi, M);
        }
        if (mi == mx) c = 'z';
        S[i] = c;
    }

    answer(S);

    return 0;
}