Can't enter double variable

Question

import java.util.Scanner;


    public static void main(String[] args)
    {
        //Interest rate,number of years,loan amount; display the monthly total payments



        Scanner input = new Scanner(System.in);
        //Ask for interest rate
        System.out.println("Enter your interest rate : ");


        //Get interest rate
        double interestRate = input.nextDouble();

        //Ask number of years
        System.out.println("Enter the number of years for this loan : ");


        //Get number of years
        double numberOfYears = input.nextDouble();

        //Ask for loan amount
        System.out.println("Enter your loan amount : ");
        //Get loan amount
        double loanAmount = input.nextDouble();


        //Monthly interest rate
        double monthlyInterestRate = interestRate / 12;

        //Monthly payment
        double monthlyPayment = (loanAmount * monthlyInterestRate) /
                1 - 1 / Math.pow(1 + monthlyInterestRate, numberOfYears*12)
                ;

        //Total payment
        System.out.println("total payment is : " + monthlyPayment * 12 * numberOfYears);
    }

When I enter a interest rate as my first input, for example 2.5 or 2.0 it gives

Exception in thread "main" java.util.InputMismatchException
        at java.util.Scanner.throwFor(Unknown Source)
        at java.util.Scanner.next(Unknown Source)
        at java.util.Scanner.nextDouble(Unknown Source)
        at Sal.main(Sal.java:17)

I put in double variable, it wants integer. I don't understand. And yes I did import Scanner and type my class. I bought my computer 1 week ago. Same code should work fine because it was from my exercise book.