说明：  给定含有n 个元素的多重集合S = {a1, a2,., an } ，1 ≤ ai ≤ n ，1 ≤ i ≤ n ，每个元素在S 中出现的次数称为该元素的重数。多重集S 中重数大于n/2 的元素称为主元素。例如，S={2，2，4，2，1，2，5，2，2，8}。多重集S 的主元素是2，其重数为6。
(Given n elements containing multiple collection S = (a1, a2,., An), 1 ≤ ai ≤ n, 1 ≤ i ≤ n, each element appearing in the number of S is called the multiplicity of elements. S multiple sets of weight more than n/2 elements as the main element. For example, S = (2,2,4,2,1,2,5,2,2,8). Multiple sets of the main elements of S is 2, its multiplicity is 6.)