Write a `x2x` matrix which is both symmetric and skew-symmetric.

Explanation

For a symmetric matrix `A` with transpose `A^T`,

`A= A^T->(1)`

For a skew-symmetric matrix `A`,

`A= -A^T->(2)`

Adding (1) and (2),

`2A = 0`

`=>A = 0`

So, matrix `A` will have all elements as `0`.

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