#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  string t(n, 'a');
  string s(n, '.');
  rep(i, n) {
    int c[25]{};
    rep(j, 25) {
      t[i] = 'a' + j;
      cout << "? " << t << endl;
      cin >> c[j];
    }
    if (count(all(c), c[0]) == 25) {
      s[i] = 'z';
    } else {
      s[i] = 'a' + (max_element(all(c)) - c);
    }
  }
  cout << "! " << s << endl;
}