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 Rust (1.42.0) (judge verdict: Accepted)

use std::io::{stdin, stdout, Read, Write};
fn main() {
    let mut buffer = Vec::new();
    let stdin = stdin();
    let mut handle = stdin.lock();
    handle.read_to_end(&mut buffer).unwrap();
    let mut outbuf = Vec::new();
    for &c in buffer.iter().step_by(2) {
        outbuf.push(c);
    }
    outbuf.push(b'\n');
    stdout().write(&outbuf).unwrap();
}