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 Ruby (2.3.3) (judge verdict: Accepted)

require 'pp'

def gets; ARGF.gets; end

class Solver

  def initialize
  end

  def main
    s = gets.chomp

    ans = ""

    s.each_char.with_index do |c, i|
      ans += c if (i+1).odd?
    end

    puts ans
  end
end

if __FILE__ == $0
  Solver.new.main
end