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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#define REP(i, n) for (int i = 0; i < (n); i++)
using namespace std;

int main(void) {
    cin.tie(0);
    ios::sync_with_stdio(false);

    string str;
    cin >> str;

    string tmp;
    REP(i, str.size()) {
        if (i % 2 == 0)
            tmp += str[i];
    }

    cout << tmp << '\n';
    return 0;
}