
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
A $7 \times 7$ board has a chessboard coloring. In one move, you can select any $m \times n$ rectangle of cells and change all its cells to the opposite color (so that black cells become white, and white cells become black). What is the minimum number of moves required to make the entire board a single color?

Present the answer in LaTex format: \boxed{Your answer}
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