/*

     题意：一个字符串分割成k段，每段开头字母不相同

     水题：记录每个字母出现的次数，每一次分割把首字母的次数降为0，最后一段直接全部输出

 */

 #include <cstdio>

 #include <iostream>

 #include <cstring>

 #include <string>

 #include <algorithm>

 using namespace std;

 const int MAXN = 1e2 + ;

 const int INF = 0x3f3f3f3f;

 char s[MAXN];

 int num[];

 int main(void)        //Codeforces Round #302 (Div. 2) A Set of Strings

 {

     //freopen ("A.in", "r", stdin);

     int k;

     while (scanf ("%d", &k) == )

     {

         scanf ("%s", &s);

         if (k == )    {puts ("YES");    printf ("%s\n", s);    continue;}

         memset (num, , sizeof (num));

         int len = strlen (s);

         for (int i=; i<len; ++i)    num[s[i]-'a']++;

         int t = ;

         for (int i=; i<; ++i)    if (num[i])    ++t;

         if (t < k)    {puts ("NO");    continue;}

         puts ("YES");

         printf ("%c", s[]);    num[s[]-'a'] = ;

         int p = ;    int i;

         for (i=; i<len; ++i)

         {

             if (!num[s[i]-'a'])    {printf ("%c", s[i]);}

             else

             {

                 num[s[i]-'a'] = ;    puts ("");

                 printf ("%c", s[i]);    ++p;

             }

             if (p == k - )    break;

         }

         for (int j=i+; j<len; ++j)    printf ("%c", s[j]);

         puts ("");

     }

     return ;

 }