The students are playing games on the playground. Everyone forms a square, one person stands at each vertex, and 18 students stand on each side. How many students are playing games in total?
同学们在操场上玩游戏，大家围成一个正方形，每个顶点各站一人，每边站18个同学，一共有多少个同学在玩游戏？
<result>48</result>