约瑟夫游戏

people={}
for x in range(1,31):
    people[x]=1
# print(people)
check=0
i=1
j=0
while i<=31:
    if i == 31:
        i=1
    elif j == 15:
        break
    else:
        if people[i] == 0:
            i+=1
            continue
        else:
            check+=1
            if check == 9
                people[i]=0
                check = 0
                print("{}号下船了".format(i))
                j+=1
            else:
                i+=1
                continue
    

  File "<ipython-input-1-093c8aed4432>", line 19
    if check == 9
                 ^
SyntaxError: invalid syntax