Reverse First N Characters

You are given a string s and an integer n. Your task is to reverse the first n characters of s. If n is greater than the length of s, then return the original string unchanged.

In other words, if we denote the string as:

$$s = s_1s_2\dots s_{|s|},$$

then the required output is:

$$ \text{result} = \begin{cases} \left(s_1s_2\dots s_{n}\right)^R s_{n+1}s_{n+2}\dots s_{|s|} & \text{if } n \leq |s|, \\ s & \text{if } n > |s|, \end{cases}$$

where \((s_1s_2\dots s_n)^R\) denotes the reverse of the first n characters.

inputFormat

The input consists of two lines:

• The first line is a non-empty string s (it can be empty as well).
• The second line is an integer n.

You should read the input from standard input (stdin).

outputFormat

Output the transformed string after reversing its first n characters if possible. The result should be printed to standard output (stdout).

## sample

abcdef
3

cbadef