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;

namespace AOJ_Practice
{
    class Program
    {
        static void Main(string[] args)
        {
            var oneLine = Console.ReadLine();

            StringBuilder strs = new StringBuilder();
            for (int i = 0; i < oneLine.Length; i++)
            {
                if (char.IsUpper(oneLine[i]))
                {
                    strs.Append(char.ToLower(oneLine[i]));
                }
                else if(char.IsLower(oneLine[i]))
                {
                    strs.Append(char.ToUpper(oneLine[i]));
                }
                else
                {
                    strs.Append(oneLine[i]);
                }
            }

            Console.WriteLine(strs.ToString());
        }
    }
}