Grid Painting Problem

You are given an integer \(N\). Your task is to paint an \(N \times N\) grid with two distinct colors represented by the numbers 1 and 2. The grid must be painted in an alternating pattern similar to a chessboard:

• If \(N\) is even, fill the grid so that adjacent cells (horizontally and vertically) have different numbers. In other words, the cell at row \(i\) and column \(j\) should be painted with 1 if \(i+j\) is even, and 2 if \(i+j\) is odd.
• If \(N\) is odd (i.e. \(N \mod 2 \neq 0\)), output Not possible since a perfectly balanced alternating partition is not feasible.

Example:

For \(N=2\), a valid output is:

1 2
2 1

inputFormat

The input consists of a single integer \(N\) provided via standard input (stdin).

outputFormat

If \(N\) is even, output the \(N \times N\) grid with alternating 1s and 2s. Each row should be printed on a separate line with the numbers separated by a single space.

If \(N\) is odd, output the string Not possible.

## sample

2

1 2
2 1

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