30 students line up in a line from low to high according to their heights. The height difference between two adjacent students is the same. The sum of the heights of the top 10 students is 1450 cm, and the sum of the heights of the top 20 students is 3030 cm. Then the 30 What is the sum of the heights of the students in centimeters?
30名同学按照身高由低到高排成一队，相邻两个同学的身高差都相同，前10名同学的身高和是1450厘米，前20名同学的身高和是3030厘米，那么这30名同学的身高和是多少厘米．
<result>4_730</result>