Problem:
Score : 200 points

Problem Statement

You are given a string s consisting of lowercase English letters. Extract all the characters in the odd-indexed positions and print the string obtained by concatenating them. Here, the leftmost character is assigned the index 1.

Constraints

Each character in s is a lowercase English letter.

1≤|s|≤10^5

Input

The input is given from Standard Input in the following format:

s

Output

Print the string obtained by concatenating all the characters in the odd-numbered positions.

Sample Input 1

atcoder

Sample Output 1

acdr

Extract the first character a, the third character c, the fifth character d and the seventh character r to obtain acdr.

Sample Input 2

aaaa

Sample Output 2

aa

Sample Input 3

z

Sample Output 3

z

Sample Input 4

fukuokayamaguchi

Sample Output 4

fkoaaauh

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

program ABC072B
    implicit none
    integer(8)::i
    integer(8)::t_len=1
    character(100000)::s,t
    read(5,*)s

    do i=1,len_trim(s)
        if(mod(i,2)==1)then
            t(t_len:t_len)=s(i:i)
            t_len=t_len+1
        end if
    end do

    print'(A)',t(1:t_len-1)
end program ABC072B