class Numeric
  @@currencies = {'dollar' => 1, 'yen' => 0.013, 'euro' => 1.292, 'rupee' => 0.019}
  def method_missing(method_id)
    singular_currency = method_id.to_s.gsub( /s$/, '')
    if @@currencies.has_key?(from_currency)
      self / @@currencies[from_currency]
    else
      super
    end
  end
  def in(symbol) 
    @@currencies = {'dollar' => 1, 'yen' => 0.013, 'euro' => 1.292, 'rupee' => 0.019}
    singular_currency = symbol.to_s.gsub( /s$/, '')
    if @@currencies.has_key?(from_currency)
      self * @@currencies[from_currency]
    end
  end      
end
 
print 3.dollar.in(:dollar)

CmNsYXNzIE51bWVyaWMKICBAQGN1cnJlbmNpZXMgPSB7J2RvbGxhcicgPT4gMSwgJ3llbicgPT4gMC4wMTMsICdldXJvJyA9PiAxLjI5MiwgJ3J1cGVlJyA9PiAwLjAxOX0KICBkZWYgbWV0aG9kX21pc3NpbmcobWV0aG9kX2lkKQogICAgc2luZ3VsYXJfY3VycmVuY3kgPSBtZXRob2RfaWQudG9fcy5nc3ViKCAvcyQvLCAnJykKICAgIGlmIEBAY3VycmVuY2llcy5oYXNfa2V5Pyhmcm9tX2N1cnJlbmN5KQogICAgICBzZWxmIC8gQEBjdXJyZW5jaWVzW2Zyb21fY3VycmVuY3ldCiAgICBlbHNlCiAgICAgIHN1cGVyCiAgICBlbmQKICBlbmQKICBkZWYgaW4oc3ltYm9sKSAKICAgIEBAY3VycmVuY2llcyA9IHsnZG9sbGFyJyA9PiAxLCAneWVuJyA9PiAwLjAxMywgJ2V1cm8nID0+IDEuMjkyLCAncnVwZWUnID0+IDAuMDE5fQogICAgc2luZ3VsYXJfY3VycmVuY3kgPSBzeW1ib2wudG9fcy5nc3ViKCAvcyQvLCAnJykKICAgIGlmIEBAY3VycmVuY2llcy5oYXNfa2V5Pyhmcm9tX2N1cnJlbmN5KQogICAgICBzZWxmICogQEBjdXJyZW5jaWVzW2Zyb21fY3VycmVuY3ldCiAgICBlbmQKICBlbmQgICAgICAKZW5kCgpwcmludCAzLmRvbGxhci5pbig6ZG9sbGFyKQ==