S = input()
N = len(S)
i = 0
j = 0
op = {"+","-"}
tmp1 = 0
op1 = 1
while i + j < N:
    if S[i+j] == "(":
        tmp2 = 0
        op2 = 1
        j += 1
        while S[i+j] != ")":
            if S[i + j] not in op:
                if op2 == 1:
                    tmp2 += int(S[i + j])
                else:
                    tmp2 -= int(S[i + j])
            else:
                if S[i + j] == "+":
                    op2 = 1
                else:
                    op2 = 0
            j += 1
        if op1 == 1:
            tmp1 += tmp2
        else:
            tmp1 -= tmp2

    else:
        if S[i+j] not in op:
            if op1 == 1:
                tmp1 += int(S[i+j])
            else:
                tmp1 -= int(S[i+j])
        else:
            if S[i+j] == "+":
                op1 = 1
            else:
                op1 = 0
    i += 1
print(tmp1)