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)

str = gets
ans = ""
str.length.times do |i|
  tmp = str[i..i]
  if "a" <= tmp && tmp <= "z"
    tmp = (tmp.ord - "a".ord + "A".ord).chr
  elsif "A" <= tmp && tmp <= "Z"
    tmp = (tmp.ord - "A".ord + "a".ord).chr
  end
  ans += tmp
end
print ans