a, b=input().split()
c=a+b
n=len(c)
ans=0
p=1
x=0
for i in range(n):
    if c[i]=='+' or c[i]=='-':
        ans+=p*x
        if c[i]=='+':
            p=1
        else:
            p=-1
        x=0
    else:
        x*=10
        x+=int(c[i])
ans+=p*x
print(ans)