
str = gets.chomp.split("")
str_downcase = []
str_upcase = []

str.each do |val|
  str_downcase << val.downcase
end

str.each do |val|
  str_upcase << val.upcase
end

ans = []

str.each_with_index do |val, ind|
  if val != str_upcase[ind]
    ans << str_upcase[ind]
  else
    ans << str_downcase[ind]
  end
end

puts ans.join