[1, 2, 3, 4, 1, 1] set([1, 2, 3, 4]) 4 set([1, 2, 3, 4]) 4 set([1, 2, 3, 4]) 5 set([1, 2, 3, 4, 100]) 4 set([1, 2, 3, 4]) 4 set([1, 3, 4, 100]) 4 set([1, 2, 3, 4])