f = input()

def cal(x):
    sq = list(x)
    sm = int(sq[0])
    for i in range((len(sq)-1)//2):
        if sq[2*i+1] == '+':
            sm += int(sq[2*(i+1)])
        else:
            sm -= int(sq[2*(i+1)])
    return sm

ro = []
lo = []
for i in range(len(f)):
    if f[i] == '(':
        ro.append(i)
    elif f[i] == ')':
        lo.append(i)
        
        
pls = []
for i in range(len(ro)):
    p = f[ro[i]+1:lo[i]]
    pls.append(p)
    
for i in pls:
    f = f.replace("("+i+")",str(cal(i)))

f = f.replace('--','+')
f = f.replace('+-','-')
a = cal(f)
print(a)