#include <bits/stdc++.h>
using namespace std;
long long i, j, k, l, n, m, x, y, a[1000000], b[30];
string s;
int main() {
  ios_base::sync_with_stdio(NULL);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> s;
  for (i = 0; i < s.size(); i++) a[s[i] - 96]++;
  for (i = 1; i <= 26; i++)
    if (a[i] > 0) l++;
  if (l < n) {
    cout << "NO";
    exit(0);
  }
  cout << "YES" << endl;
  l = 1;
  b[s[0] - 96] = 1;
  for (i = 0; i < s.size(); i++) {
    cout << s[i];
    if (s[i] != s[i + 1] && b[s[i + 1] - 96] == 0)
      if (l < n && n != 1) {
        b[s[i + 1] - 96] = 1;
        l++;
        cout << endl;
      }
  }
}
