#include <bits/stdc++.h>
using namespace std;
int k;
string s;
vector<string> ans;
bool all[26];
int main() {
  ios_base::sync_with_stdio(0);
  cin >> k >> s;
  string build = "";
  for (int i = 0; i < s.size(); ++i)
    if (!all[s[i] - 'a']) {
      if (!build.empty()) ans.push_back(build);
      build = s[i];
      all[s[i] - 'a'] = 1;
    } else
      build += s[i];
  ans.push_back(build);
  if (ans.size() < k)
    cout << "NO";
  else {
    cout << "YES"
         << "\n";
    while (ans.size() > k) {
      int last = ans.size() - 1;
      string s1 = ans[last], s2 = ans[last - 1];
      ans.pop_back();
      ans.pop_back();
      ans.push_back(s2 + s1);
    }
    for (int i = 0; i < ans.size(); ++i) cout << ans[i] << "\n";
  }
  return 0;
}
