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 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>

int main()
{
    char s[100000+1]; //[]付け忘れないように
    int i = 0;

    scanf("%s", s); //文字列を入力するときは&付けない

    while (s[i] >= 'a' && s[i] <= 'z') //文字列の最後の文字まで。\０でやる。!=EOFにしない。
    {
            printf("%c", s[i]); //文字列じゃなくて文字を出力するので%c
            i += 2;
    }
    
    printf("\n");
    return 0;
}