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

int main() {
    int n;
    cin >> n;
    vector<char> ans(n);
    for (int i = 0; i < n; i++) {
        vector<int> num;
        string ask = "";
        for (int j = 0; j < n; j++) {
            ask += "a";
        }
        for (char c = 'a'; c < 'z'; c++) {
            ask[i] = c;
            cout << "? " << ask << endl;
            int cnt;
            cin >> cnt;
            num.push_back(cnt);
        }
        int id = max_element(num.begin(), num.end()) - num.begin();
        bool same = true;
        for (int j = 0; j < (int)num.size() - 1; j++) {
            if (num[j] != num[j + 1]) {
                same = false;
            }
        }
        ans[i] = (same ? 'z' : (char)(id + 97));
    }
    cout << "! ";
    for (auto c : ans) {
        cout << c;
    }
    cout << endl;
    return 0;
}