<qa>  How many arms will patients be enrolled in?A total of 1.803 patients will be enrolled in 4 arms. Patients will either be treated with anastrozole 1mg daily for 3 years or tamoxifen 20mg daily for 3 years, and will additionally receive either zoledronate 8mg q4 weeks for 3 years or no zoledronate arm A: Nolvadex alone; arm B: Nolvadex plus zoledronate; arm C: Arimidex alone; arm D: Arimidex plus zoledronate. 