using System;class Demo {static void Main() {int a = 20, b = 70, c = 40, d = 90;Console.WriteLine({0} {1} {2} {3}, a, b, c, d);

using System;namespace MyApplication {class Factorial {public int display(int n) {int res = 1;while (n != 1) {

using System;class Program {static void Main() {string str = 1001;Console.WriteLine(Integer:+ConvertClass.Convert(str));

using System;class Program {static void Main() {string str = Hello World! Hello!;Console.WriteLine(Occurrence:+Check.CheckOccurrences(str, Hello));

using System;public class Demo {public static void Main() {int a = 0 , myWord = 1;string str = Hello World!;

using System;namespace Demo {class myApplication {static void Main(string[] args) {string str = Amit$#%;

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace Demo {class MyApplication {

using System;using System.Collections.Generic;using System.Text;namespace Demo {class MyApplication {

using System;using System.Collections.Generic;using System.Text;namespace Demo {class MyApplication {

using System;using System.Collections.Generic;using System.Text;namespace Demo {class MyApplication {

using System;namespace ArrayApplication {class MyArray {static void Main(string[] args) {int [] n = new int[5];

using System;public abstract class Vehicle {public abstract void display();}public class Bus : Vehicle {

using System;class Program {static void Main() {string str1 = Tom;// concatenationstring str2 = Hanks + str1;