Diagonal Difference

Given a square matrix, your task is to calculate the absolute difference between the sum of its primary diagonal and the sum of its secondary diagonal.

The primary diagonal is given by: $$ \sum_{i=0}^{n-1} a_{i,i} $$ and the secondary diagonal is given by: $$ \sum_{i=0}^{n-1} a_{i,n-i-1} $$.

You will be provided with T test cases. For each test case, first an integer n is given indicating the size of the square matrix, followed by n lines each containing n space-separated integers.

For each test case, output the computed absolute difference on a new line.

inputFormat

The input is read from stdin and has the following format:

• The first line contains a single integer T, the number of test cases.
• For each test case:
  • The first line contains an integer n, the size of the square matrix.
  • The next n lines each contain n space-separated integers representing the matrix.

outputFormat

For each test case, output a single integer — the absolute difference between the sum of the primary diagonal and the sum of the secondary diagonal. Each result should be printed on a new line to stdout.

## sample

1
1
1

0

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