CF544A.Set of Strings

You are given a string q. A sequence of k strings _s_1, _s_2, ..., s__k is called beautiful, if the concatenation of these strings is string q (formally, _s_1 + _s_2 + ... + s__k = q) and the first characters of these strings are distinct.

Find any beautiful sequence of strings or determine that the beautiful sequence doesn't exist.

给你一个字符串 $q$。若 $k$ 个字符串 $s_1,\ s_2,\ \dots,\ s_k$ 满足：这些字符串的拼接结果为字符串 $q$（即形式化地，$s_1 + s_2 + \dots + s_k = q$），且这些字符串的首字符互不相同，则称该序列是“优美的”。

请找出任意一个优美的字符串序列；若不存在这样的序列，则判定其不存在。

The first line contains a positive integer k (1 ≤ k ≤ 26) — the number of strings that should be in a beautiful sequence.

The second line contains string q, consisting of lowercase Latin letters. The length of the string is within range from 1 to 100, inclusive.

第一行包含一个正整数 $k$（$1 \leq k \leq 26$）—— 表示优美序列中应包含的字符串数量。

第二行包含一个字符串 $q$，由小写拉丁字母组成。该字符串的长度在 $1$ 到 $100$ 之间（含端点）。

If such sequence doesn't exist, then print in a single line "NO" (without the quotes). Otherwise, print in the first line "YES" (without the quotes) and in the next k lines print the beautiful sequence of strings _s_1, _s_2, ..., s__k.

If there are multiple possible answers, print any of them.

如果不存在这样的序列，则在一行中输出 "NO"（不带引号）。否则，在第一行输出 "YES"（不带引号），并在接下来的 $k$ 行中输出优美的字符串序列 $s_1,\ s_2,\ \dots,\ s_k$。

如果存在多个可能的答案，输出任意一个即可。

In the second sample there are two possible answers: {"aaaca", "s"} and {"aaa", "cas"}.

在第二个样例中，存在两种可能的答案：{"aaaca", "s"} 和 {"aaa", "cas"}。