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