#include <bits/stdc++.h>
using namespace std;
string s, tmp;
int n;
vector<string> vt;
bool arr[26];
int idx = 0;
int main() {
  cin >> n >> s;
  arr[s[0] - 'a'] = true;
  for (int i = 0; i < s.size(); i++) {
    if (!arr[s[i] - 'a']) {
      arr[s[i] - 'a'] = true;
      tmp = "";
      for (int j = idx; j < i; j++) {
        tmp += s[j];
      }
      vt.push_back(tmp);
      idx = i;
    }
  }
  tmp = "";
  for (int i = idx; i < s.size(); i++) {
    tmp += s[i];
  }
  vt.push_back(tmp);
  if (vt.size() >= n) {
    cout << "YES" << endl;
    for (int i = 0; i < n; i++) {
      cout << vt[i];
      if (i != n - 1) cout << endl;
    }
    for (int i = n; i < vt.size(); i++) {
      cout << vt[i];
    }
    cout << endl;
    return 0;
  }
  cout << "NO" << endl;
  return 0;
}
