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.Text;

namespace ITP1_8_A
{
    class Program
    {
        static void Main(string[] args)
        {
            string text = Console.ReadLine();
            StringBuilder sb = new StringBuilder();
            for(int i = 0; i < text.Length; i++)
            {
                char ch = text[i];
                if ('A' <= ch && ch <= 'Z')
                    sb.Append(char.ToLower(ch));
                else if ('a' <= ch && ch <= 'z')
                    sb.Append(char.ToUpper(ch));
                else
                    sb.Append(ch);
            }
            Console.WriteLine(sb);
        }
    }
}