import sequtils,strutils
var
    S = stdin.readline
    a,b,c,k,p,p2 : int
    f : bool
S &= '='
p = 1
proc ctoi(c : char) : int =
    c.ord - '0'.ord
for i,a in S:
    if a.isdigit:
        b *= 10
        b += a.ctoi
    elif a == '-':
        if f:
            c += b * p2
            p2 = -1
        else:
            k += b * p
            p = -1
        b = 0
    elif a == '+':
        if f:
            c += b * p2
            p2 = 1
        else:
            k += b * p
            p = 1
        b = 0
    elif a == '(':
        c = 0
        p2 = 1
        f = true
    elif a == ')':
        c += b * p2
        b = c
        f = false
k += b * p
echo k