#!/usr/bin/ruby
# -*- coding: utf-8 -*-
=begin
ITP1-ITP1_8-A

Character - Toggling Cases
Time Limit : 1 sec, Memory Limit : 65536 KB
??§????????¨?°????????????\?????????

????????????????????????????°?????????¨??§???????????\????????????????????°????????????????????????????????????
Input

????????????1???????????????????????????
Output

????????????????????????????°?????????¨??§???????????\??????????????????????????????????????????????????¢????????????????????\???????????????????????????????????????????????????
Constraints

    ??\?????????????????????????????? < 1200

Sample Input

fAIR, LATER, OCCASIONALLY CLOUDY.

Sample Output

Fair, later, occasionally cloudy.

=end
fh=STDIN
#fh=open("IPT1_8_A.txt")
s=fh.gets.chomp
puts s.swapcase