CF770A.New Password

Innokentiy decides to change the password in the social net "Contact!", but he is too lazy to invent a new password by himself. That is why he needs your help.

Innokentiy decides that new password should satisfy the following conditions:

• the length of the password must be equal to n,
• the password should consist only of lowercase Latin letters,
• the number of distinct symbols in the password must be equal to k,
• any two consecutive symbols in the password must be distinct.

Your task is to help Innokentiy and to invent a new password which will satisfy all given conditions.

因诺肯季决定更改社交网络“Contact!”的密码，但他懒得自己设计新密码，因此需要你的帮助。

因诺肯季认为新密码必须满足以下条件：

• 密码长度必须恰好为 $n$；
• 密码只能由小写拉丁字母组成；
• 密码中不同字符的个数必须恰好为 $k$；
• 密码中任意两个相邻字符必须互不相同。

你的任务是帮助因诺肯季设计一个满足所有给定条件的新密码。

The first line contains two positive integers n and k (2 ≤ n ≤ 100, 2 ≤ k ≤ min(n, 26)) — the length of the password and the number of distinct symbols in it.

Pay attention that a desired new password always exists.

第一行包含两个正整数 $n$ 和 $k$（$2 \leq n \leq 100$，$2 \leq k \leq \min(n, 26)$）—— 分别表示密码的长度以及其中不同符号的个数。

注意：所要求的新密码一定存在。

Print any password which satisfies all conditions given by Innokentiy.

输出任意一个满足 Innokentiy 给出的所有条件的密码。

In the first test there is one of the appropriate new passwords — java, because its length is equal to 4 and 3 distinct lowercase letters a, j and v are used in it.

In the second test there is one of the appropriate new passwords — python, because its length is equal to 6 and it consists of 6 distinct lowercase letters.

In the third test there is one of the appropriate new passwords — phphp, because its length is equal to 5 and 2 distinct lowercase letters p and h are used in it.

Pay attention the condition that no two identical symbols are consecutive is correct for all appropriate passwords in tests.

在第一个测试中，一个符合要求的新密码是 java，因为其长度为 4，且其中使用了 3 个互不相同的小写字母：a、j 和 v。

在第二个测试中，一个符合要求的新密码是 python，因为其长度为 6，且由 6 个互不相同的小写字母组成。

在第三个测试中，一个符合要求的新密码是 phphp，因为其长度为 5，且其中使用了 2 个互不相同的小写字母：p 和 h。

请注意：所有测试中符合要求的密码均满足“不存在两个相邻的相同字符”这一条件。