#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 10;
const int mod = 1e9 + 7;
const int inf = 0x3f3f3f3f;
map<string, int> s1, s2;
void ask(int l, int r) {
  cout << "? " << l << ' ' << r << '\n';
  cout.flush();
}
void solve(map<string, int>& s, int n) {
  int num = (n + 1) * n / 2;
  string a;
  for (int i = (1); i <= (num); i++) {
    cin >> a;
    sort(a.begin(), a.end());
    s[a]++;
  }
}
int num[30];
char Find(string a, string b) {
  memset(num, 0, sizeof(num));
  for (int i = (0); i <= (b.size() - 1); i++) num[b[i] - 'a']++;
  if (a.size() > 0)
    for (int i = (0); i <= (a.size() - 1); i++) num[a[i] - 'a']--;
  for (int i = (0); i <= (26); i++)
    if (num[i]) return i + 'a';
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  if (n == 1) {
    ask(1, 1);
    solve(s1, 1);
    cout << "! " << s1.begin()->first << '\n';
    cout.flush();
  } else {
    ask(1, n);
    solve(s1, n);
    ask(2, n);
    solve(s2, n - 1);
    for (auto x : s2) {
      s1[x.first] -= x.second;
    }
    string ans = "";
    for (int i = (1); i <= (n); i++) {
      for (auto x : s1) {
        if (x.second != 0 && (x.first).size() == i) {
          ans += Find(ans, x.first);
          break;
        }
      }
    }
    cout << "! " << ans << '\n';
    cout.flush();
  }
  return 0;
}
