B'This problem is actually a subproblem of problem G from the same contest. There are n candies in a candy box. The type of the i -th candy is a_i ( 1 <= a_i <= n ). You have to prepare a gift using some of these candies with the following restriction: the numbers of candies of each type presented in a gift should be all distinct (i. xe2 x80 x89e. for example, a gift having two candies of type 1 and two candies of type 2 is bad). It is possible that multiple types of candies are completely absent from the gift. It is also possible that not all candies of some types will be taken to a gift. Your task is to find out the maximum possible size of the single gift you can prepare using the candies you have. You have to answer q independent queries. If you are Python programmer, consider using PyPy instead of Python when you submit your code. The first line of the input contains one integer q ( 1 <= q <= 2 cdot 10^5 ) -- the number of queries. Each query is represented by two lines. The first line of each query contains one integer n ( 1 <= n <= 2 cdot 10^5 ) -- the number of candies. The second line of each query contains n integers a_1, a_2, ... , a_n ( 1 <= a_i <= n ), where a_i is the type of the i -th candy in the box. It is guaranteed that the sum of n over all queries does not exceed 2 cdot 10^5 . For each query print one integer -- the maximum possible size of the single gift you can compose using candies you got in this query with the restriction described in the problem statement. In the first query, you can prepare a gift with two candies of type 8 and one candy of type 5 , totalling to 3 candies. Note that this is not the only possible solution -- taking two candies of type 4 and one candy of type 6 is also valid. '...