Problem:
Toggling Cases

Write a program which converts uppercase/lowercase letters to lowercase/uppercase for a given string.

Input

A string is given in a line.

Output

Print the converted string in a line. Note that you do not need to convert any characters other than alphabetical letters.

Constraints

The length of the input string < 1200

Sample Input

fAIR, LATER, OCCASIONALLY CLOUDY.

Sample Output

Fair, later, occasionally cloudy.

Solution in C# (judge verdict: Accepted)

using System;

namespace aoj8a
{
    class Program
    {
        static void Main(string[] args)
        {
            /*1?????????????????????????????????char???????????????????????????*/
            char[] line = (Console.ReadLine()).ToCharArray();

            for (int i = 0; i < line.Length; i++)
            {
                line[i] = changeCtype(line[i]);     //??§??????????°??????????????°????????????§?????????????????????????????????
            }

            string str = new string(line);
            Console.WriteLine(str);
        }

        private static char changeCtype(char ch)
        {
            if (char.IsUpper(ch))       //??§????????§????????°
            {
                ch = char.ToLower(ch);
                return ch;              //?°??????????????????????
            }
            else if (char.IsLower(ch))  //?°?????????§????????°
            {
                ch = char.ToUpper(ch);
                return ch;              //??§?????????????????????
            }
            else
            {
                /*nop*/
                return ch;              //???????????§??????????????°??????????????????
            }
           
        }
    }
}