#include <bits/stdc++.h>
using namespace std;
const long long dx[] = {1, 0, -1, 0};
const long long dy[] = {0, 1, 0, -1};
long long ans;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  string s;
  cin >> s;
  vector<vector<char> > v(n);
  int cntr = 0;
  map<char, int> mp;
  for (int i = 0; i < s.size(); i++) {
    if (i == 0) {
      v[0].push_back(s[0]);
      mp[s[i]]++;
      continue;
    }
    if (!mp[s[i]] and cntr < n - 1) {
      cntr++;
      mp[s[i]]++;
      v[cntr].push_back(s[i]);
    } else {
      v[cntr].push_back(s[i]);
    }
  }
  if (cntr == n - 1) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
    return 0;
  }
  for (int i = 0; i < n; i++) {
    for (auto j : v[i]) {
      cout << j;
    }
    cout << endl;
  }
  return 0;
}
