import java.util.Scanner;        public class test {
          public static void main(String[] args)    {
                 int a;               Scanner input=new Scanner(System.in);               System.out.print("Enter a number between 0-1000:");               int b=input.nextInt();         if(b >= 0 && b <= 1000)         {
                 a= b%10 + b/10%10 + b/100%10 +b/1000;               System.out.println("Sum of several numbers "+a);         }         else         {
              System.out.println("Error!");         }    } } 2.15 import java.util.Scanner; public class test {
       public static void main(String[] args)     {
           Scanner input=new Scanner(System.in);         double x1,x2,y1,y2;         System.out.println("Enter the x1 ");         x1 = Double.valueOf(input.nextInt());         System.out.println("Enter the y1 ");         y1 = Double.valueOf(input.nextInt());         System.out.println("Enter the x2 ");         x2 = Double.valueOf(input.nextInt());         System.out.println("Enter the y2 ");         y2 = Double.valueOf(input.nextInt());         System.out.println("The distance between the two points is "+ Math.pow((Math.pow((x2 - x1),2)+Math.pow((y2 - y1),2)),0.5));     } }