def solve(line):
    neg = False
    tmpneg = False
    sum = 0
    for i, c in enumerate(line):
        if c == "-":
            tmpneg = True

        if c == "(" and i > 0 and line[i - 1] == "-":
            neg = True
        elif c == ")":
            neg = False

        if c.isdigit():
            if tmpneg == neg:
                sum += int(c)
            else:
                sum -= int(c)

        if c != "-":
            tmpneg = False
    return sum

if __name__ == "__main__":
    print(solve(input()))