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 _1_8_a
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            char[] c = s.ToCharArray();
          
            for (int i = 0; i < s.Length; i++)
            {
                if (char.IsUpper(c[i]))
                {
                    c[i] = char.ToLower(c[i]);
                }
                else if (char.IsLower(c[i]))
                {
                    c[i] = char.ToUpper(c[i]);
                }
            }
            Console.WriteLine(c);
            Console.ReadKey();
        }
    }
}