num=[0 for i in range(1024)]
a=input().split()
b=input().split()
for i in range(-1,-1025,-1):
    m,n=__________
    if __________:
        m=int(a[i])
    if __________:
        n=int(b[i])
    num[i]=__________
    if __________:
        k=__________
for i in range(-1,-1025,-1):

    ...
    ...

if k:
    print("-",end="")
__________
for i in num:
    if i!=0:
        __________
    if f:
        print(i,end="")