func f(s: []char, i: &int): int
	var res: int :: @g(s, &i)
	while(true)
		if(i >= ^s)
			ret res
		end if
		switch c(s[i])
		case '+', '-'
			do i :+ 1
			do res :+ @g(s, &i) * (c = '-' ?(-1, 1))
		default
			do i :+ 1
			ret res
		end switch
	end while
	ret 0
end func

func g(s: []char, i: &int): int
	if(i >= ^s)
		ret 0
	end if
	switch c(s[i])
	case '0' to '9'
		do i :+ 1
		ret c $ int - '0' $ int
	case '('
		do i :+ 1
		ret @f(s, &i)
	end switch
	ret 0
end func

func main()
	var s: []char :: cui@input()
	var i: int :: 0
	var ans: int :: @f(s, &i)
	do cui@print("\{ans}\n")
end func