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# (.NET Core 3.1.201) (judge verdict: Accepted)

 using System;
using System.Collections.Generic;

class Program
{
    static void Main(string[] args)
    {
        var s = Console.ReadLine();

        var res = new List<char>();
        for(var i = 0; i < s.Length; i++)
        {
            if ((i + 1) % 2 != 0) 
                res.Add(s[i]);
        }
        
        Console.WriteLine(string.Join("", res));
    }
}