```ruby
# frozen_string_literal: true

module Buckaruby
  module Currency
    EURO = "EUR"
  end
end
```

Add currencies GBP and USD.
user
```ruby
# frozen_string_literal: true

module Buckaruby
  module Currency
    EURO = "EUR"
    BRITISH_POUND = "GBP"
    US_DOLLAR = "USD"
  end
end
```
assistant