Easy To Resolve

class Program    {        static void Main(string[] args)
        {             Console.WriteLine("\t\t\t\tWelcome To WAKFA Story Competetion");
            Console.WriteLine("\nOrganizers are:\n\t\tSyed Ahsan Raza");
            Console.WriteLine("\t\tFaisal Mukhtar");
            Console.WriteLine("\t\tAqsa Ghaffar");
            Console.WriteLine("\t\tKhadija Amjad");
            Console.WriteLine("\t\tWadiya Ali\n");
            Console.WriteLine("\n(NOTE) Story with the best moral lesson will be considered as the best one.\n\t\t\tStory should be 50-100 words.\n\t\t\t\tGood luck !\n");
            Console.WriteLine("Please enter your story.");
            string Story = Console.ReadLine();
            Console.WriteLine("\n----------------------------\n");
            Console.WriteLine("Here is your story:\n\t" + "'' " + Story + " ''");
            while (true)
            {                Console.WriteLine("\n\t\t\t\tDo you want to make any changes?(Y/N)");
                char a = Convert.ToChar(Console.ReadLine());
                if (a == 'y' || a == 'Y')
                {                    Console.WriteLine("Please select the operation:\n 1.Contains \t\t\t 2.Lowercase");
                    Console.WriteLine(" 3.Uppercase \t\t\t 4.Insert ");
                    Console.WriteLine(" 5.Length \t\t\t 6.Remove ");
                    Console.WriteLine(" 7.Replace \t\t\t 8.Split ");
                    Console.WriteLine(" 9.Trim \t\t\t 10.Index");
                    Console.WriteLine(" 11.Substring \t\t\t 12.Endswith");
                    int n = Convert.ToInt32(Console.ReadLine());
                    switch (n)
                    {                        case 1:
                            Console.WriteLine("CONTAIN \n Enter the word you want to find:");
                            string b = Console.ReadLine();
                            Contain(Story, b);                            break;
                        case 2:
                            Lowercase(Story);                            break;
                        case 3:
                            Console.WriteLine("UPPERCASE \n Enter the word you want to change to uppercase:");
                            string d = Console.ReadLine();
                            Uppercase(Story, d);                            break;
                        case 4:
                            Console.WriteLine("Enter the word before which you want to insert something");
                            string Valuee = Console.ReadLine();
                            Console.WriteLine("Now enter the word/words you want to insert");
                            string change = Console.ReadLine();
                            Insert(Story, Valuee,change);                            break;
                        case 5:
                         
                            Length(Story);                            break;
                        case 6:
                            Console.WriteLine("REMOVE \n Enter the word you want to remove:");
                            string g = Console.ReadLine();
                            Remove(Story, g);                            break;
                        case 7:
                            Console.WriteLine("REPLACE \n Find:");
                            string h = Console.ReadLine();
                            Console.WriteLine("Replace with:");
                            string i = Console.ReadLine();
                            Replace(Story, h, i);                            break;
                        case 8:
                            Program.Split(Story);
                            break;
                        case 9:
                            Trim(Story);                            break;
                        case 10:
                            Console.WriteLine("INDEX\nEnter the word");
                            string k = Console.ReadLine();
                            Console.WriteLine("Index of the word is");
                            Console.WriteLine( Index (Story,k));
                            break;
                        case 11:
                            Program.substring(Story);
                            break;
                        case 12:
                            Program.endswith(Story);
                            break;
                        default:
                            Console.WriteLine("Invalid Selection..!");
                            break;
                     }                 
                }                else                {                    break;
                }            }        }        public static void Contain(string a, string b)
        {            Console.WriteLine(a.Contains(b));
        }        public static void  Lowercase(string a)
        {            Console.WriteLine("LOWERCASE \n Enter the word you want to change to lowercase:");
            string c = Console.ReadLine();
            Console.WriteLine(a.Replace(c,c.ToLower()));
        }        public static void Uppercase(string a, string b)
        {            Console.WriteLine(a.Replace(b, b.ToUpper()));
        }        public static void Insert(string a, string b,string c)
        {         
            Console.WriteLine(a.Insert(Index(a,b)," "+c));
        }        public static void Length(string a)
        {            int Length = a.Length;
            Console.WriteLine("Length of your string is " + Length);
        }        public static void Remove(string a, string b)
        {            Console.WriteLine(a.Remove(Index(a, b),b.Length));
         
        }        public static void Replace(string a, string b, string c)
        {            Console.WriteLine(a.Replace(b, c));
        }        public static void Split(string a)
        {            Console.WriteLine("SPLIT \nEnter a Character From where do you want to split your document?");
            char b = Convert.ToChar(Console.ReadLine());
            string[] array = a.Split(b);
            foreach(string word in array)
            {                Console.WriteLine(word);
            }        }        public static void Trim(string a)
        {            Console.WriteLine("Your story is successfully trimmed.");
            Console.WriteLine("-----------------------------------");
            Console.WriteLine(a.Trim());
        }        public static int Index(string a,string b)
        {            int Position =a.IndexOf(b);
            return Position;
        }        public static void substring(string sedo)
        {            Console.WriteLine("Enter the Starting string value: ");
            int first = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter the lenght of string value: ");
            int final = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine();
            Console.WriteLine(sedo.Substring(first, final));
        }        public static void endswith(string redo)
        {            Console.WriteLine("Enter the Word for Endswith Method: ");
            string nope = Console.ReadLine();
            Console.WriteLine(redo.EndsWith(nope));
        }        }     }