Product

import java.io.*;
public class product
{
public static void main(String[] args)throws IOException
{
BufferedReader keyboard =new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter a list of number.");
System.out.println("Please enter one number one line.");
System.out.println("Enter negative number to end");
String numString = keyboard.readLine();
double num = Double.parseDouble(numString.trim());
double product=1;
while(num>=0)
{
product=num*product;
numString = keyboard.readLine();
num = Double.parseDouble(numString.trim());
}
System.out.println("Product:"+product);
System.exit(0);
}
}