Problem:
Score : 100 points

Problem Statement

We have a 3×3 square grid, where each square contains a lowercase English letters.
The letter in the square at the i-th row from the top and j-th column from the left is c_{ij}.

Print the string of length 3 that can be obtained by concatenating the letters in the squares on the diagonal connecting the top-left and bottom-right corner of the grid, from the top-left to bottom-right.

Constraints

Input consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

c_{11}c_{12}c_{13}
c_{21}c_{22}c_{23}
c_{31}c_{32}c_{33}

Output

Print the string of length 3 that can be obtained by concatenating the letters on the diagonal connecting the top-left and bottom-right corner of the grid, from the top-left to bottom-right.

Sample Input 1

ant
obe
rec

Sample Output 1

abc

The letters in the squares on the diagonal connecting the top-left and bottom-right corner of the grid are a, b and c from top-right to bottom-left. Concatenate these letters and print abc.

Sample Input 2

edu
cat
ion

Sample Output 2

ean

Solution in PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
//Request Question
function getq($get_word=null){
	if($get_word===null){
		return str_replace("\n","",fgets(STDIN));
	}else if($get_word===1){
		return explode(" ",str_replace("\n","",fgets(STDIN)));
	}
}

/*		START		*/
$b=0;
$c=getq(1);
for ($i=$c[0]; $i <= $c[1]; $i++) {
	if($i==strrev($i)){
		$b++;
	}
}
echo "$b\n";
?>