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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main
{

  public static void main
  (
    String[] args
  )
  {
    BufferedReader in_stream;
    String         in_str;

    String[] in_C;

    int cnt;

    try
    {
      in_stream = new BufferedReader(new InputStreamReader(System.in));

      /*----------------
       * 引数
       *----------------*/
      in_C = new String[9];
      for(cnt=0; cnt<3; cnt++)
      {
        in_str = new String(in_stream.readLine());

        in_C[(cnt*3) + 0] = in_str.substring(0, 1);
        in_C[(cnt*3) + 1] = in_str.substring(1, 2);
        in_C[(cnt*3) + 2] = in_str.substring(2, 3);
      }

      System.out.println(in_C[0] + in_C[4] + in_C[8]);
    }
    catch(Exception e)
    {
      e.printStackTrace();
    }
  }
}