#include <bits/stdc++.h>
using namespace std;
char s[1010], ans[1010];
struct node {
  int cnt[26], sum;
  void in() {
    scanf("%s", s);
    int len = strlen(s);
    memset(cnt, 0, sizeof(cnt)), sum = len;
    for (int i = 0; i < len; i++) cnt[s[i] - 'a']++;
  }
} nw, f[1010], O;
bool operator<(node A, node B) {
  for (int i = 0; i < 26; i++)
    if (A.cnt[i] != B.cnt[i]) {
      if (A.cnt[i] < B.cnt[i]) return 1;
      return 0;
    }
  return 0;
}
int n;
map<node, int> ma1, ma2;
map<node, int>::iterator it1, it2;
char operator-(node A, node B) {
  for (int i = 0; i < 26; i++)
    if (A.cnt[i] != B.cnt[i]) return i + 'a';
  return '0';
}
int main() {
  for (int i = 0; i < 26; i++) O.cnt[i] = 0;
  O.sum = 0, f[0] = O;
  scanf("%d", &n);
  if (n <= 3) {
    for (int i = 1; i <= n; i++) {
      printf("? %d %d\n", i, i), fflush(stdout);
      scanf("%s", s), ans[i] = s[0];
    }
    printf("! ");
    for (int i = 1; i <= n; i++) putchar(ans[i]);
    return puts(""), 0;
  }
  printf("? 1 %d\n", n), ma1.clear(), ma2.clear(), fflush(stdout);
  for (int i = 1; i <= n * (n + 1) / 2; i++) nw.in(), ma1[nw]++;
  printf("? 2 %d\n", n), fflush(stdout);
  for (int i = 1; i <= n * (n - 1) / 2; i++) nw.in(), ma2[nw]++;
  for (it2 = ma2.begin(), it1 = ma1.begin(); it1 != ma1.end(); it1++) {
    if (it2 == ma2.end() || ((*it2).first - (*it1).first) != '0') {
      f[(*it1).first.sum] = (*it1).first;
    } else {
      if ((*it1).second != (*it2).second) f[(*it1).first.sum] = (*it1).first;
      it2++;
    }
  }
  printf("! ");
  for (int i = 1; i <= n; i++) putchar(f[i] - f[i - 1]);
  puts("");
  return 0;
}
