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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 compute_nb_samples(in_prefix):
 """Check the number of samples. :param in_prefix: the prefix of the input file. :type in_prefix: str :returns: the number of sample in ``prefix.fam``. """

    file_name = in_prefix + ".tfam"
    nb = None
    with open(file_name, 'rb') as input_file:
        nb = len(input_file.readlines())
    return nb