def logic(number: int) -> int:
    """Perform logic for even-odd transformation.

    Each even-odd transformation:
        * Adds two (+2) to each odd integer.
        * Subtracts two (-2) to each even integer.
    """
    # Determine the modifier based on number being even or odd.
    modifier = -2 if number % 2 == 0 else 2
    return number + modifier