def get_maxdepth(input_table_A,input_table_B):
    """Get maximum depth between tables"""
    #gaps and overlaps
    maxlist=[]
    a= input_table_A['todepth'].unique().tolist()
    maxlist.append(a[-1])
    b= input_table_B['todepth'].unique().tolist()
    maxlist.append(b[-1])
    maxl=float(max(maxlist))
    return maxl