84669 person learning
152542 person learning
20005 person learning
5487 person learning
7821 person learning
359900 person learning
3350 person learning
180660 person learning
48569 person learning
18603 person learning
40936 person learning
1549 person learning
1183 person learning
32909 person learning
100人,100个灯,现在灯是灭状态,这100人起来打开自己整数倍的灯,最后房间那个灯是亮着的