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 Perl (v5.18.2) (judge verdict: Accepted)

use v5.18;
use warnings;
use utf8;
sub line { chomp(my $str = <>); $str; }
sub split_line { (split / /, line) }

my @s = split //, line;
my @ans;
for my $i (0 .. $#s) {
  if ($i % 2 == 0) {
    push @ans, $s[$i];
  }
}
say join '', @ans;