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 Go (1.6) (judge verdict: Wrong Answer)

package main

import (
	"bufio"
	"fmt"
	"os"
)

var reader = bufio.NewReader(os.Stdin)

func nextLine() string {
	var buf, line []byte
	isPrefix := true
	var err error
	for isPrefix {
		buf, isPrefix, err = reader.ReadLine()
		if err != nil {
			panic(err)
		}
		line = append(line, buf...)
	}
	return string(line)
}
func main() {
	s := nextLine()
	bs := make([]byte, len(s)/2+1)
	for i := 0; i < len(s); i += 2 {
		bs[i/2] = s[i]
	}
	fmt.Println(string(bs))
}