s = "#" + input()
t = ""
a = []
op = []
for i in range(1, len(s)):
    # 数字の直後の符号のみop
    if s[i] in ('+', '-') and s[i - 1].isdigit():
        op.append(s[i])
        a.append(t)
        t = ""
    else:
        t += s[i]
if t != "":
    a.append(t)

a = list(map(int, a))
ans = a[0]
for i in range(len(op)):
    if op[i] == '+':
        ans -= a[i + 1]
    else:
        ans += a[i + 1]
print(ans)