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# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

namespace ABC_090_A_Csharp_ver
{
    class Program
    {
        static void Main(string[] args)
        {
            var word = Console.ReadLine();
            var wort = Console.ReadLine();
            var wors = Console.ReadLine();
            char c11 = word[0];char c12 = word[1];char c13 = word[2];
            char c21 = wort[0];char c22 = wort[1];char c23 = wort[2];
            char c31 = wors[0];char c32 = wors[1];char c33 = wors[2];
            string a = c11.ToString();
            string b = c22.ToString();
            string c = c33.ToString();
            Console.WriteLine(a + b + c);
            Console.ReadKey();
        }
    }
}