s = input()
ans = 0
pas = -1
pm = "+"

for i in range(len(s)):
    if s[i] == "(":
        a = int(s[i+1])
        b = int(s[i+3])
        if s[i+2] == "+":
            if pm == "+":
                ans += a+b
            else:
                ans -= a+b
        else:
            if pm == "+":
                ans += a-b
            else:
                ans -= a-b
        pas += 1

    if pas == -1:
        if s[i] == "+":
            pm = "+"
        elif s[i] == "-":
            pm = "-"
        else:
            if pm == "+":
                ans += int(s[i])
            else:
                ans -= int(s[i])
    elif pas == 4:
        pas = -1
    else:
        pas += 1

print(ans)