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.

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.

Constraints

• Each character in s is a lowercase English letter.
• 1≤|s|≤10^5

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

见题面 Input 部分

见题面 Output 部分