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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 merge(files, out_file, config):
 """merge smartly fastq files. It recognizes paired fastq files."""

    pair1 = [fastq_file[0] for fastq_file in files]
    if len(files[0]) > 1:
        path = splitext_plus(out_file)
        pair1_out_file = path[0] + "_R1" + path[1]
        pair2 = [fastq_file[1] for fastq_file in files]
        pair2_out_file = path[0] + "_R2" + path[1]
        _merge_list_fastqs(pair1, pair1_out_file, config)
        _merge_list_fastqs(pair2, pair2_out_file, config)
        return [pair1_out_file, pair2_out_file]
    else:
        return _merge_list_fastqs(pair1, out_file, config)