#include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     string s;     cin >> s;     set<char> ss;     for (char c : s) ss.insert(c);     if (ss.size() < n)       cout <<  NO  << endl;     else {       cout <<  YES  << endl;       int vis[30];       memset(vis, 0, sizeof vis);       string res =   ;       for (char c : s) {         if (n == 1)           res += c;         else {           if (res.size() > 0 and !vis[c -  a ]) {             n--;             vis[c -  a ] = 1;             cout << res << endl;             res = string(1, c);           } else {             vis[c -  a ] = 1;             res += c;           }         }       }       cout << res << endl;     }     return 0;   }   