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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 concatenate_fastas(output_fna_clustered, output_fna_failures, output_concat_filepath):
 """ Concatenates two input fastas, writes to output_concat_filepath output_fna_clustered: fasta of successful ref clusters output_fna_failures: de novo fasta of cluster failures output_concat_filepath: path to write combined fastas to """


    output_fp = open(output_concat_filepath, "w")

    for label, seq in parse_fasta(open(output_fna_clustered, "U")):
        output_fp.write(">%s\n%s\n" % (label, seq))
    for label, seq in parse_fasta(open(output_fna_failures, "U")):
        output_fp.write(">%s\n%s\n" % (label, seq))

    return output_concat_filepath