def complement(seq):
    """
    Complement the sequence
    :param seq: "ATATCTC"
    :return: "TATGAG"
    """
    alpha = {
        "A": "T",
        "T": "A",
        "G": "C",
        "C": "G",
        "N": "N"
    }
    return ''.join([alpha[i] for i in list(seq)])