Execute Ruby Online

class Binar
    def binar
        print "Input number to convert: "
        number = gets.to_i
        numerical_system = nil

        until(1..3).include?(numerical_system)      
            print "Select numeric system to convert: 1.Binar 2.Octal 3.Hexadecimal"
            numerical_system = gets.chomp
        end
        
        if numerical_system == 1
            y = number.to_s(2)
            s = "Binar"
        elsif numerical_system == 2
            y = number.to_s(8)
            s = "Octal"
        else
            y = number.to_s(16)
            s = "Hexadecimal"
        end
        
        print "#{number} in #{s} numerical system is #{y}"
    end
end

convert = Binar.new
convert.binar