Given a square matrix, calculate the absolute difference between the sums of its diagonals.
For example, the square matrix is shown below:
1 2 3
4 5 6
9 8 9  
The left-to-right diagonal = . The right to left diagonal = . Their absolute difference is .
Function description
Complete the function in the editor below.
diagonalDifference takes the following parameter:
- int arr[n][m]: an array of integers
Return
- int: the absolute diagonal difference
Input Format
The first line contains a single integer, ,  the number of rows and columns in the square matrix . 
Each of the next  lines describes a row, , and consists of  space-separated integers .
Constraints
Output Format
Return 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