#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<string> v;
  map<char, int> m;
  int k;
  cin >> k;
  string q;
  cin >> q;
  int l = q.size();
  int flag = 1;
  int cnt = 0;
  string s;
  if (l < k) {
    cout << "NO";
    return 0;
  } else {
    cnt = 1;
    s += q[0];
    m[q[0]] = 1;
    for (int i = 1; i < l; i++) {
      if (m[q[i]] == 0 and cnt < k) {
        m[q[i]] += 1;
        cnt++;
        v.push_back(s);
        s = "";
        s += q[i];
      } else {
        s += q[i];
      }
    }
    v.push_back(s);
  }
  if (v.size() == k) {
    cout << "YES" << endl;
    for (int i = 0; i < v.size(); i++) cout << v[i] << endl;
  } else {
    cout << "NO" << endl;
  }
}
