Problem:
Score : 200 points

Problem Statement

You are given a string S consisting of lowercase English letters.
We will write down this string, starting a new line after every w letters. Print the string obtained by concatenating the letters at the beginnings of these lines from top to bottom.

Constraints

1 \leq w \leq |S| \leq 1000

S consists of lowercase English letters.

w is an integer.

Input

Input is given from Standard Input in the following format:

S
w

Output

Print the desired string in one line.

Sample Input 1

abcdefgh
3

Sample Output 1

adg

When we write down abcdefgh, starting a new line after every three letters, we get the following:

abc

def

gh

Concatenating the letters at the beginnings of these lines, we obtain adg.

Sample Input 2

lllll
1

Sample Output 2

lllll

Sample Input 3

souuundhound
2

Sample Output 3

suudon

Solution in Rust (1.42.0) (judge verdict: Accepted)

#![allow(unused_imports)]

use text_io::*;
use proconio::*;
use std::collections::*;
use itertools::Itertools;
use std::process::exit;
use std::cmp::*;
use num::*;
use num::integer::Roots;

fn main() {
    input! {
    a:String,
    b:usize,
    }
    let mut a=a.chars().collect_vec();
    let mut v:Vec<char>=Vec::new();
    for i in 0..a.len() {
        if i%b==0{v.push(a[i])}
    }
    let v:String=v.iter().collect();
    println!("{}",v)
}