Answers

2014-06-14T16:23:41+08:00
{ } , {0} , {1}, {2}, {3}, {0,1}, {2,3} ,{0,2} {0,3}, {1,2}, {1,3}, {2,4} {0,1,2}, {1,2,3}, {0,1,3} {0,1,2,3}
0