s1 = input()

def calc(s):
    value = 0
    plus_flag = True
    kakko_flag = False
    in_kakko = ""
    for i in s:
        if i=="(":
            kakko_flag = True
        if kakko_flag:
            in_kakko += i
            if i==")":
                if plus_flag:
                    value += calc(in_kakko[1:-1])
                else:
                    value -= calc(in_kakko[1:-1])
                in_kakko = ""
                kakko_flag = False
        else:
            if i=="+":
                plus_flag = True
            elif i=="-":
                plus_flag = False
            else:
                if plus_flag:
                    value += int(i)
                else:
                    value -= int(i)
    return value

print(calc(s1))