p03415 AtCoder Beginner Contest 090 - Diagonal String
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.

Examples

Input

ant
obe
rec


Output

abc


Input

edu
cat
ion


Output

ean
```python
s=open(0).read().split()
print(s[0][0]+s[1][1]+s[2][2])
```