#include <iostream>
#include <deque>

using namespace std;

deque<double> operands;
deque<char> operators;

void filterInput(char input[])
{
    char ops[5] = { '+','-','*','/','=' };
    for (char item : ops)
    {
        if (input[0] == item)
        {
            operators.push_back(input[0]);
            return;
        }
    }

    operands.push_back(atof(input));
}

double calculate()
{
    double result;
    while (operators.size())
    {
        switch (operators.front())
        {
        case '+':
            result = operands[0] + operands[1];
            break;
        case '-':
            result = operands[0] - operands[1];
            break;
        case '*':
            result = operands[0] * operands[1];
            break;
        case '/':
            result = operands[0] / operands[1];
            break;
        default:
            operators.pop_front();
            break;
        }

        //pop the 1st and 2nd elements from the que
        operands.pop_front();
        operands.pop_front();
        //push in the result from the front
        operands.push_front(result);

        //pop the operator
        operators.pop_front();
    }
    return operands[0];
}

int main()
{
    char buffer[50];
    memset(buffer, 0, sizeof(buffer));

    while (!cin.eof()) //while CTRL+Z is not pressed
    {
        cin >> buffer;
        filterInput(buffer);
    }
    operands.pop_back(); // ^Z would get pushed as 0 value, so we pop it out when we exit the loop
    cout << "Result: " << calculate() << endl;
    system("pause");
    return 0;
}