class WowCode
    attr_reader :s

    def initialize(s: "")
        @s = s
        @alphabet = ('A'..'Z').to_a
    end

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

    def decoding(str)
        str = str.split("")
        r = str.each_with_index.map do |c, i|
            @alphabet[((c.ord-(i+1))-("A".ord)) % @alphabet.size]
        end
        r.join("")
    end

    def result
        puts decoding(@s)
    end

    def run
        cause
        result
    end
end

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