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

//#if 1
//#include"pch.h"
//#define _CRT_SECURE_NO_WARNINGS
//#endif
#include<stdio.h>
#include<stdlib.h>
#include<cmath>
#include<math.h>
#include<string>
#include<string.h>
#include<algorithm>
#include<iostream>
using namespace std;
int main() {
	char c[3][3];
	string ans;
	for (int i = 0; i < 3; i++) {
		for (int j = 0; j < 3; j++) {
			cin >> c[i][j];
			if (i == j)ans += c[i][j];
		}
	}
	cout << ans << endl;
	
	return(0);
}