Extract Every Nth Character

Background

Congcong has recently been learning about string processing. He encountered an interesting task that requires extracting characters from a string at a specific step size.

Problem Description

Given a non-empty string $S$ and an integer $N$, return a new string. This new string is formed by taking characters from the original string $S$ starting at index $0$, and then every $N$-th character thereafter. For example, if $N$ is $3$, the new string will contain characters from indices $0, 3, 6, \dots$ of the original string. $N$ is guaranteed to be $1$ or more.

Input Format

Input is given from Standard Input in the following format.

S N

Where $S$ is a non-empty string and $N$ is an integer.

Output Format

Output is printed to Standard Output in the following format.

result_string

Where result_string is the new string extracted according to the rules.

Sample

Miracle
2

Mrce

abcdefg
2

aceg

abcdefg
3

adg

Sample Explanation

For the first sample, the input string is Miracle and $N=2$. Starting from index $0$, characters are extracted every $2$ positions, i.e., characters at indices $0, 2, 4, 6$. These characters are M, r, c, e respectively, which combine to form Mrce.

Constraints

The length of string $S$ is between $1$ and $10^5$. The integer $N$ is between $1$ and the length of string $S$. Time limit: $1$ second Memory limit: $1024$ KiB