s_0 = list(input())

def calc(s):
	N = len(s)
	ans = int(s[0])
	num = False
	plus = True
	for i in range(1,N):
		if num:
			if plus:
				ans += int(s[i])
			else:
				ans -= int(s[i])
			num = False
		else:
			if s[i] == '+':
				plus = True
			else:
				plus = False
			num = True
	return ans
			
while '(' in s_0:
	left = s_0.index('(')
	right = s_0.index(')')
	s_dush = s_0[left+1:right]
	ans = calc(s_dush)
	s_0 = s_0[:left] + [str(ans)] + s_0[right+1:]
	
print(calc(s_0))