Diagonal Difference

Given a square matrix, calculate the absolute difference between the sums of its diagonals.

Input Format

The first line contains a single integer,  denoting the number of rows and columns in the matrix . 
The next  lines denote the matrix 's rows, with each line containing  space-separated integers describing the columns.

Constraints

Output Format

Print the absolute difference between the sums of the matrix's two diagonals as a single integer.

Sample Input

3
11 2 4
4 5 6
10 8 -12

Sample Output

15

Explanation

The primary diagonal is:

11
   5
     -12

Sum across the primary diagonal: 11 + 5 - 12 = 4

The secondary diagonal is:

     4
   5
10

Sum across the secondary diagonal: 4 + 5 + 10 = 19 
Difference: |4 - 19| = 15

Note: |x| is the absolute value of x

Solution:

Python Code

#!/bin/python3

import os
import sys

#
# Complete the diagonalDifference function below.
#
def diagonalDifference(a):
    #
    # Write your code here.
    #
    sum1=sum(a[i][i] for i in range(n))
    sum2=sum(a[i][n-i-1] for i in range(n))
    return abs(sum1-sum2)
            
      


if __name__ == '__main__':
    f = open(os.environ['OUTPUT_PATH'], 'w')

    n = int(input())

    a = []

    for _ in range(n):
        a.append(list(map(int, input().rstrip().split())))

    result = diagonalDifference(a)

    f.write(str(result) + '\n')

    f.close()