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)

conv = Hash[*("A".."Z").zip("a".."z").map {|a| [a, a.reverse] }.flatten]
puts gets.gsub(/#{conv.keys.join('|')}/) { conv[$&] }