S = input()

i = 0
ans = 0
sgn = 1
flag = True
while i < len(S):
    if S[i] == "+" and flag:
        i += 1
        continue
    elif S[i] == "+":
        sgn = -1
    elif S[i] == "-" and flag:
        sgn = -1
    elif S[i] == "-":
        sgn = 1
    elif S[i] == "(" and i > 0 and S[i-1] == "-":
        flag = False
    elif S[i] == "(":
        i += 1
        continue
    elif S[i] == ")":
        flag = True
    else:
        ans += sgn*int(S[i])
    i += 1
print(ans)