import java.util.Scanner;
import java.util.Stack;
import java.lang.*;
public class Infix {
    public static double calculations(String here) {
        Scanner input = new Scanner(System.in);
        MyStack<Character> operatorstack =  new MyStack<Character>();
        MyStack<Double> valuestack = new MyStack<Double>();
String operator;
char topOperator;
char nextCharacter;
double operandTwo;
double operandOne;
double result;
double next;

while(input.hasNext())
{
    if(input.hasNextDouble() ){
        next = input.nextDouble();
        valuestack.push(next);
    }
    else {
        operator = input.next();
        nextCharacter = operator.charAt(0);

        switch(nextCharacter) {

        case '^':
            operatorstack.push(nextCharacter);
            break;
        case '+':
        case '-':
        case '*':
        case '/':
            while(!operatorstack.isEmpty()&& getPriority(nextCharacter) <= getPriority(operatorstack.peek()))
            {
                // Calculate operator at the top of the stack.
                topOperator = operatorstack.pop();
                operandTwo = valuestack.pop();
                operandOne = valuestack.pop();

        if (topOperator == '*')
            result = operandOne * operandTwo;
        else if (topOperator == '/')
            result = operandOne / operandTwo;
        else if (topOperator == '+')
            result = operandOne + operandTwo;
        else if (topOperator == '-')
            result = operandOne - operandTwo;
        else
            throw new RuntimeException("You can't do that, illegal operator: " + topOperator);
        valuestack.push(result);
            topOperator = operatorstack.pop();
            }
            break;
        default:
            break;
        }
    }
        while(!operatorstack.isEmpty()){
            topOperator = operatorstack.pop();
            operandTwo = valuestack.pop();
            operandOne = valuestack.pop();

        if (topOperator == '*')
            result = operandOne * operandTwo;
        else if (topOperator == '/')
            result = operandOne / operandTwo;
        else if (topOperator == '+')
            result = operandOne + operandTwo;
        else if (topOperator == '-')
            result = operandOne - operandTwo;
        else
            throw new RuntimeException("You can't do that, illegal operator: " + topOperator);
            valuestack.push(result);

        }
        double answer = valuestack.peek();
        return answer;
    }
    }

    public static int getPriority(char nextCharacter) {
        if (nextCharacter == '*' || nextCharacter == '/')
                return 1;
        else if (nextCharacter == '+' || nextCharacter == '-')
                return 2;
        else if (nextCharacter == '=')
                return 3;
        else
                return Integer.MIN_VALUE;
    }
    }