Given a square matrix of size , calculate the absolute difference between the sums of its diagonals.
Input Format
The first line contains a single integer, . 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 two sums of the matrix's 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 absolute value function
