def insert(rcd, insert_at_junctions, genotype):
    """
    Given the genotype (ie the junction that was chosen), returns the corresponding insert
    """
    junctions = ["x", "y", "z"]
    if genotype[1] != "-":
        j = junctions.index(genotype[1])
        return insert_at_junctions[j]
    else:
        return "-"