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 C (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>

int main()
{
    char S[1001] = {}, hoge[1001] = {};
    int w, i, len = 0;
    scanf(" %s %d", &S, &w);

    for(i = 0; i < 1001; i++)
    {
        if(S[i] != 0){len++;}
    }

    for(i = 0; i < len; i++)
    {
        if((i+w)%w == 0){hoge[i/w] = S[i];}
    }
    printf("%s", hoge);

    return 0;
}