#1541 잃어버린 괄호

text = list(input().split('-'))
list = []

for t in text: 
  num = 0
  for n in t.split("+"):
    num += int(n)
    
  list.append(num)  

sum = list[0]

for i in range(1,len(list)):
  sum -= list[i]

print(sum)