#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  set<char> ss;
  for (char c : s) ss.insert(c);
  if (ss.size() < n)
    cout << "NO" << endl;
  else {
    cout << "YES" << endl;
    int vis[30];
    memset(vis, 0, sizeof vis);
    string res = "";
    for (char c : s) {
      if (n == 1)
        res += c;
      else {
        if (res.size() > 0 and !vis[c - 'a']) {
          n--;
          vis[c - 'a'] = 1;
          cout << res << endl;
          res = string(1, c);
        } else {
          vis[c - 'a'] = 1;
          res += c;
        }
      }
    }
    cout << res << endl;
  }
  return 0;
}
