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)

input_strings = gets.chomp.chars
length = input_strings.length
for i in 0..(length-1)
  if input_strings[i] != input_strings[i].upcase
    input_strings[i].upcase!
  else input_strings[i] != input_strings[i].downcase
    input_strings[i].downcase!
  end
end
puts input_strings.join