from collections import deque
import math
string_expression = deque(input().split(" "))
numbers = deque()
actions = []
result = None



while string_expression:
    num = string_expression[0]
    if num.lstrip("-").isdigit():
        numbers.append(int(num))
        string_expression.popleft()
    else:
        actions.append(num)
        string_expression.popleft()
    if actions:
        action = actions[0]
        actions.pop()
        while numbers:
            if result == None:
                if action == "+":
                    result = numbers.popleft() + numbers.popleft()
                elif action == "-":
                    result = numbers.popleft() - numbers.popleft()
                elif action == "*":
                    result = numbers.popleft() * numbers.popleft()
                elif action == "/":
                    result = math.floor(numbers.popleft() / numbers.popleft())
            else:
                if action == "+":
                    result += numbers.popleft()
                elif action == "-":
                    result = result - numbers.popleft()
                elif action == "*":
                    result *= numbers.popleft()
                elif action == "/":
                    result = math.floor(result / numbers.popleft())



print(result)