def magazine_serial_check(string):
    issn_number = string
    is_it = False
    len_of_it = False
    index_number = 3
    if issn_number.__contains__("-"):
        is_it = True
        issn_number = issn_number.replace("-", "")
    if len(issn_number) == 8:
        len_of_it = True
    if is_it == True & len_of_it == True:
        return print("ISSN-sarjanumero on oikeassa muodossa")
    if is_it == False or len_of_it == False:
        return print("Ei ole oikeassa muodossa")


issn = input("Anna lehden ISSN-sarjanumero: \n")
check_issn = magazine_serial_check(issn)
print(check_issn)