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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def score_n4(matrix, matrix_size):
 """\ Implements the penalty score feature 4. ISO/IEC 18004:2015(E) -- 7.8.3 Evaluation of data masking results - Table 11 (page 54) =========================================== ==================================== ====== Feature Evaluation condition Points =========================================== ==================================== ====== Proportion of dark modules in entire symbol 50 × (5 × k)% to 50 × (5 × (k + 1))% N4 × k =========================================== ==================================== ====== N4 = 10 :param matrix: The matrix to evaluate :param matrix_size: The width (or height) of the matrix. :return int: The penalty score (feature 4) of the matrix. """

    dark_modules = sum(map(sum, matrix))
    total_modules = matrix_size ** 2
    k = int(abs(dark_modules * 2 - total_modules) * 10 // total_modules)
    return 10 * k