Waterloo180616 - Problem Set - 美力程青少儿编程

	ID	Problem Show tags Hide tags	AC / Tried	Difficulty
	507	P507 How Big Is It? Waterloo180616	0 / 0	(None)
	508	P508 Pousse Waterloo180616	0 / 0	(None)

Pick a problem randomly based on the current filter.