#include <bits/stdc++.h>

using namespace std;

void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    fast_io();
    int n;
    cin >> n;
    string ans(n, 'a');
    for (int i = 0; i < n; i++) {
        vector<int> cnt(25);
        for (int j = 0; j < 25; j++) {
            ans[i] = 'a' + j;
            cout << "? " << ans << endl;
            cin >> cnt[j];
        }
        bool all_same = true;
        int ma_idx = 0;
        for (int j = 1; j < 25; j++) {
            if (cnt[j] != cnt[ma_idx]) {
                all_same = false;
            }
            if (cnt[j] > cnt[ma_idx]) {
                ma_idx = j;
            }
        }
        if (all_same) {
            ans[i] = 'z';
        } else {
            ans[i] = 'a' + ma_idx;
        }
    }
    cout << "! " << ans << endl;
}