Problem:
Capitalize

Write a program which replace all the lower-case letters of a given text with the corresponding captital letters.

Input

A text including lower-case letters, periods, and space is given in a line. The number of characters in the text is less than or equal to 200.

Output

Print the converted text.

Sample Input

this is a pen.

Output for the Sample Input

THIS IS A PEN.

Solution in C# (judge verdict: Wrong Answer)

using System;

namespace _0512
{
    class Program
    {
        static void Main(string[] args)
        {
            //     string[] a = new string { "a" };
            string str = Console.ReadLine();

            for (int i = 0; i < str.Length; i++)
            {
                string a = str.Substring(i, 1);
                if (a == null) { Console.Write(" "); }
                else if (a == ".") { Console.WriteLine("."); }
                else if (str.Substring(i, 1) == "a") { Console.Write("A"); }
                else if (str.Substring(i, 1) == "b") { Console.Write("B"); }
                else if (a == "c") { Console.Write("C"); }
                else if (a == "d") { Console.Write("D"); }
                if (a == "e") { Console.Write("E"); }
                else
                if (a == "f") { Console.Write("F"); }
                else if (a == "g")
                {
                    Console.Write("G");
                }

                else if (a == "h") { Console.Write("H"); }

                else if (a == "i") { Console.Write("I"); }
                else if (a == "j") { Console.Write("J"); }
                else if (a == "k") { Console.Write("K"); }
                else if (a == "l") { Console.Write("L"); }
                else if (a == "m") { Console.Write("M"); }
                else if (a == "n") { Console.Write("N"); }
                else if (a == "o") { Console.Write("O"); }
                else if (a == "p") { Console.Write("P"); }
                else if (a == "q") { Console.Write("Q"); }
                else if (a == "r") { Console.Write("R"); }
                else if (a == "s") { Console.Write("S"); }

                else if (a == "t")
                {
                    Console.Write("T");
                }

                else if (a == "u") { Console.Write("U"); }
            
                else if (a == "v") { Console.Write("V"); }

                else if (a == "w") { Console.Write("W"); }

                else if (a == "x") { Console.Write("X"); }

                else if (a == "y") { Console.Write("Y"); }

                else if (a == "z") { Console.Write("Z"); }
                if (i == str.Length - 1) { Console.WriteLine(); }

            }
            Console.ReadLine();
        }

    }

}