import java.io.*;
class Pyramid{
   public static void main(String args[]){
    int x,y;
int rows = 4;
for (y = 1; y <= rows; ++y) {
    for (x = y; x < rows; ++x) {
        System.out.print(" ");
    }
    for (x = 0; x < y; ++x) {
     System.out.print((y+x) % 10);
    }
    for (x = y - 1; x > 0; --x) {
      System.out.print((y+x-1) % 10);
    }
    System.out.println();
}

   }
}

import java.util.*;
class MenuDrivenExample
{
    public static void main(String[] args) 
    {
        boolean exit=false;
        Scanner input=new Scanner(System.in);
        System.out.println("1 Convert Decimal to Binary");
        System.out.println("2 Convert Binary to Decimal");
        System.out.println("3 Exit");
        do{
        System.out.print("Enter your choice: ");
        int choice=input.nextInt();
        switch(choice){
            case 1: 
                System.out.print("Enter Decimal Number: ");
                int i = input.nextInt();  
                String bi = Integer.toBinaryString(i);
                System.out.println("Binary of "+i+" is: "+bi);
                break;

            case 2:
                System.out.print("Enter Binary Number: ");
                String str = input.next();
                  int binary= Integer.parseInt(str,2);
                  System.out.println("Decimal of "+str+" is: "+binary);
                  break;

            case 3:
                exit=true;
                System.exit(0);
                break;
          }
        }
        while(!exit);
    }
}