#include <bits/stdc++.h>
using namespace std;
long long cur, k, oz, w, l, r, i, j, k1, k2, dr, n, m, t, qt, qh, md, a[5005],
    used[5005], x, y;
string s;
vector<string> dno;
int main() {
  cin >> n >> s;
  l = 0;
  for (i = 0; i < s.size();)
    if (!used[s[i]]) {
      used[s[i]] = 1;
      dno.push_back("");
      while (used[s[i]] && i < s.size()) {
        dno[l].push_back(s[i]);
        i++;
      }
      l++;
    }
  if (l < n) {
    cout << "NO" << endl;
    return 0;
  }
  cout << "YES" << endl;
  for (i = 0; i < n - 1; i++) cout << dno[i] << "\n";
  for (i = n - 1; i < l; i++) cout << dno[i];
  cout << endl;
  return 0;
}
