S = input().strip()
Num = [str(i) for i in range(10)]
A = []
flag = 0
for c in S:
    if c=="(":
        flag = 1
        a = ""
    elif c==")":
        a = eval(a)
        if a>=0:
            A.append(str(a))
        else:
            if A[-1]=="-":
                A.pop()
                A.append("+")
                A.append(str(abs(a)))
            else:
                A.pop()
                A.append(str(a))
        flag = 0
    else:
        if flag==0:
            A.append(c)
        else:
            a += c
print(eval("".join(A)))