class CapsLock
    attr_reader :s

    def initialize(s: "")
        @s = s
    end

    def datainput
        begin
            @s = gets.chomp
        rescue
            
        end
    end

    def dataoutput
        puts @s.swapcase
    end

    def run
        datainput
        dataoutput
    end
end

if $0 == __FILE__
    CapsLock.new.run
end