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

For example, the square matrix $\textbf{arr}$ is shown below:

1 2 3
4 5 6
9 8 9

The left-to-right diagonal = $1+5+9=15$. The right to left diagonal = $3+5+9=17$. Their absolute difference is $|15-17|=2$.

Function description

Complete the $\textit{diagonalDifference}$ 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, $n$, the number of rows and columns in the square matrix $\textbf{arr}$.

Each of the next $n$ lines describes a row, $arr\left[i\right]$, and consists of $n$ space-separated integers $ar r[i][j]$.

Constraints

$-100\leq arr[i][j]\leq100$

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

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