It seems like you have inputted a mathematical expression rather than mentioning anything specific that your girlfriend likes. In order to suggest a meaningful and personal anniversary gift, it would be helpful to know more about her interests, hobbies, or preferences. Please provide some additional details so that I can assist you further in finding the perfect gift for your girlfriend.
Or you can get her a star map with the date of your anniversary.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.