s = input()
nums = []
num = ''
op = ''
for i in range(len(s)):
    if '0'<=s[i]<='9':
        num += s[i]
    else:
        if i == 0:
            num += s[i]
            continue
        if '0'<=s[i-1]<='9':
            nums.append(num)
            num = ''
            op = s[i]
        else:
            num += s[i]

nums.append(num)

if op == '-':
    print(int(nums[0])+int(nums[1]))
else:
    print(int(nums[0])-int(nums[1]))