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;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {

            //入力読取。
            string strWord = Console.ReadLine();
            
            //大文字、小文字変換。
            char[] chWord = strWord.ToCharArray();
            for (int suffix = 0; suffix < chWord.Length; suffix++)
            {
                if (char.IsUpper(chWord[suffix]))
                {
                    chWord[suffix] = char.ToLower(chWord[suffix]);
                }
                else
                {
                    chWord[suffix] = char.ToUpper(chWord[suffix]);
                }
            }

            //出力
            foreach(char changeWord in chWord){
                Console.Write(changeWord);    
            }
            Console.WriteLine();
            
        }
    }

}