View difference between Paste ID: 8RPaMAHc and pPhYb790

-string str = "hello";
+using System;
-            str += " world";
+using System.Collections.Generic;
-            str = str + "!!!";
+using System.Linq;
-            Console.WriteLine(str);
+using System.Text;
 using System.Threading.Tasks;
-            StringBuilder builder = new StringBuilder();
+
-            builder.Append("Hello");
+namespace _29_12class
-            builder.Append(" ");
+{
-            builder.Append("World");
+    class Program
-            builder.Append("!!!");
+    {
         static int num;
-            Console.WriteLine(builder.ToString());
+        static bool flagIsDouble;
-            Console.ReadLine();
+
         static void Main(string[] args)
         {
             Console.WriteLine("Please enter a number:");
             string inputFromUser;
             Console.ForegroundColor = ConsoleColor.Blue;
             inputFromUser = Console.ReadLine();
             num = Int32.Parse(inputFromUser);
             //isDouble();
             func1();
 
             Console.ReadLine();
         }
         static void func1()
         {
             int tmp = num;
             for (int i = tmp; i > 0; i--)
             {
                 Console.WriteLine(num);
                 isDouble();
                 if (flagIsDouble == true)
                 {
                     if (Console.ForegroundColor == ConsoleColor.Red)
                     {
                         Console.ForegroundColor = ConsoleColor.Blue;
                     }
                     else
                     {
                         Console.ForegroundColor = ConsoleColor.Red;
                     }
 
                 }
                 num--;
 
             }
         }
         static void isDouble()
         {
             if (num%2==0 && num!=1)
             {
                 Console.WriteLine("Is double");
                 flagIsDouble = true;
             }
             else
             {
                 Console.WriteLine("Is not double");
                 flagIsDouble = false;
             }
 
         }
     }
 }