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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 count_markers_samples(prefix, file_type):
 """Counts the number of markers and samples in plink file. :param prefix: the prefix of the files. :param file_type: the file type. :type prefix: str :type file_type: str :returns: the number of markers and samples (in a tuple). """

    # The files that will need counting
    sample_file = None
    marker_file = None

    if file_type == "bfile":
        # Binary files (.bed, .bim and .fam)
        sample_file = prefix + ".fam"
        marker_file = prefix + ".bim"

    elif file_type == "file":
        # Pedfile (.ped and .map)
        sample_file = prefix + ".ped"
        marker_file = prefix + ".map"

    elif file_type == "tfile":
        # Transposed pedfile (.tped and .tfam)
        sample_file = prefix + ".tfam"
        marker_file = prefix + ".tped"

    # Counting (this may take some time)
    nb_samples = 0
    with open(sample_file, "r") as f:
        for line in f:
            nb_samples += 1

    nb_markers = 0
    with open(marker_file, "r") as f:
        for line in f:
            nb_markers += 1

    return nb_markers, nb_samples