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

int main() {
  int N;
  cin >> N;
  string S(N, 'z');
  for(int i = 0; i < N; i++) {
    vector<int> v(25);
    for(int j = 0; j < 25; j++) {
      S[i] = (char)('a' + j);
      cout << "? " + S << endl;
      cin >> v[j];
    }
    auto it_max = max_element(v.begin(), v.end());
    auto it_min = min_element(v.begin(), v.end());
    if(*it_max == *it_min) {
      S[i] = 'z';
    }else {
      int j = it_max - v.begin();
      S[i] = (char)('a' + j);
    }
  }
  cout << "! " << S << endl;
}