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: WA: Presentation Error)

using System;
using System.Text;
 
class Program
{
    static void Main()
    {
    	var s = Console.ReadLine();
    	
    	StringBuilder sb = new StringBuilder();
    	
    	foreach(var c in s.ToCharArray()) {
    		if(c >= 'a' && c <= 'z')		sb.Append(char.ToUpper(c));
    		else if(c >= 'A' && c <= 'Z')	sb.Append(char.ToLower(c));
    		else sb.Append(c);
    	}
    	
    	Console.Write(sb);
    }
}