def clean(s: str) -> str:
    s = s.replace(" ", "").replace("*", "")
    return s

def str2lst(s: str) -> list:
    s = s[:-1]
    if s[0] == "-":
        teken1 = -1
        s = s[1:]
    else:
        teken1 = 1

    if "+" in s:
        teken2 = 1
        s_list = s.split("+")
    else:  # '-'
        teken2 = -1
        s_list = s.split("-")

    s_list[0] = int(s_list[0]) * teken1
    s_list[-1] = int(s_list[-1]) * teken2
    return s_list

def lst2str(s_list: list) -> str:
    return f"{s_list[0]} {"-" if s_list[-1] < 0 else "+"} {abs(s_list[-1])} i"

def som_aid(c1: list, c2: list) -> list:
    return [c1[0] + c2[0], c1[-1] + c2[-1]]

def vermenigvuldig_aid(c1: list, c2: list) -> list:
    x1 = c1[0]*c2[0] - c1[-1]*c2[-1]
    x2 = c1[0]*c2[-1] + c1[-1] * c2[0]
    return [x1, x2]

def som(c1, c2):
    c1, c2 = clean(c1), clean(c2)
    c1, c2 = str2lst(c1), str2lst(c2)
    s = som_aid(c1, c2)
    return lst2str(s)

def vermenigvuldig(c1, c2):
    c1, c2 = clean(c1), clean(c2)
    c1, c2 = str2lst(c1), str2lst(c2)
    s = vermenigvuldig_aid(c1, c2)
    return lst2str(s)