Alternating Checkerboard Pattern

You are given a checkerboard with n rows and m columns. Your task is to fill the checkerboard with two characters, 'A' and 'B', such that the board is colored in an alternating pattern. Specifically, for a cell located at row i and column j (0-indexed), the cell is filled with 'A' if \( (i+j) \mod 2 = 0 \) and with 'B' otherwise.

For each test case, you should first output a line containing "YES" to indicate that a solution exists. Then, output the checkerboard configuration line by line.

Example:

Input:
1
2 2
Output:
YES
AB
BA

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inputFormat

The first line contains an integer T, the number of test cases. Each of the following T lines contains two space-separated integers n and m, which represent the number of rows and columns of the checkerboard respectively.

Example:

2
2 2
3 3

outputFormat

For each test case, output begins with a line containing the word "YES". Then output n lines each containing a string of length m representing the filled checkerboard.

Example:

YES
AB
BA
YES
ABA
BAB
ABA

## sample

1
1 1

YES
A

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