def calculator():

    n = input()

    def summ():
        nums = []
        while len(nums) < 2:
            nums.append(calculator())

        return nums[0] + nums[1]

    def minus():
        nums = []
        while len(nums) < 2:
            nums.append(calculator())

        return nums[0] - nums[1]

    def times():
        nums = []
        while len(nums) < 2:
            nums.append(calculator())

        return nums[0] * nums[1]

    def divide():
        nums = []
        while len(nums) < 2:
            nums.append(calculator())

        return nums[0] // nums[1]


    if n == "+":
        return summ()
    elif n == "-":
        return minus()
    elif n == "*":
        return times()
    elif n == "/":
        return divide()
    else:
        return int(n)