[Algorithmlog]Greedy#18白俊1541

expression = list(input().split('-'))
num = []
for i in expression :
    if '+' in i :
        new = map(int,i.split('+'))
        num.append(sum(new))
    else :
        num.append(int(i))
result = num[0] - sum(num[1:])

print(result)