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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;

namespace ABC072B
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            char[] t = new char[s.Length/2+1];
            int count = 0;
            for(int i = 0; i < s.Length; i++){
                if(i % 2 == 0){
                    t[count] = s[i];
                    count++;
                }
            }
            string ans = new string(t);
            Console.WriteLine(ans);
        }
    }
}