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 Fortran (gfortran v4.8.4) (judge verdict: Accepted)

program main
	implicit none
    character(1000) S, ans
	integer w, i
	read(*, *) S
	read(*, *) w
	do i = 1, len_trim(S)
		if(w == 1) then
			write(*, *) trim(S)
			goto 1
		else if(mod(i,w) == 1) then
			write(*, '(a)', advance = 'No') S(i:i)
		end if
	end do
	write(*, *) ''
1 continue
end program main