#include <bits/stdc++.h>
using namespace std;
int k;
const int N = 105;
char s[N];
int cnt[30];
int vis[N];
int main() {
  while (~scanf("%d", &k)) {
    scanf("%s", s + 1);
    int len = strlen(s + 1);
    memset(cnt, 0, sizeof(cnt));
    for (int i = 1; i <= len; i++) {
      cnt[s[i] - 'a']++;
    }
    int x = 0;
    for (int i = 0; i < 26; i++) {
      if (cnt[i]) {
        x++;
      }
    }
    if (x >= k) {
      printf("YES\n");
    } else {
      printf("NO\n");
      continue;
    }
    memset(vis, 0, sizeof(vis));
    int cc = 0;
    for (int i = 1; i <= len; i++) {
      if (cc < k && !vis[s[i] - 'a']) {
        vis[s[i] - 'a'] = 1;
        if (cc != 0) {
          printf("\n");
        }
        cc++;
      }
      printf("%c", s[i]);
    }
    printf("\n");
  }
  return 0;
}
