Forty-six students from class 6 and two teachers went to the park for a spring outing. The ticket office in the park said: "Tourists are 20 yuan per person; group tickets are 5% off for more than 20 people, and 10% off for more than 50 people." How do they buy tickets? Best deal?
六2班46名同学和两位老师去公园春游，公园售票处写着："游客每人20元；团体购票，20人以上九五折优惠，50人以上九折优惠．"他们怎样买票最合算？
<result>50</result>