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 Ruby (judge verdict: Accepted)

#!/usr/bin/env ruby

if __FILE__ == $0 then
	s = gets.split('').map(&:ord)
    s.size.times do |i|
        if s[i] > 0x40 and (s[i]-0x41)%0x20 < 0x1a then
            s[i]^=0x20
		end
	end
	puts s.map(&:chr).join('')
end