Candy Box (easy version)

本题是G题的一个子问题。 你有$n$块糖果，第$i$块糖果的种类是$a_i$。 你想选出来若干块糖果送给别人。你选出来的糖果需要满足任意两种糖果的数量都不能相等。 求你最多能够选出来多少块糖果。 你需要回答$q$组询问。 $\text{——by wucstdio}$

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 \le a_i \le 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. e. 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 \le q \le 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 \le n \le 2 \cdot 10^5 $ ) — the number of candies. The second line of each query contains $ n $ integers $ a_1, a_2, \dots, a_n $ ( $ 1 \le a_i \le 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.

3
8
1 4 8 4 5 6 3 8
16
2 1 3 3 4 3 4 4 1 3 2 2 2 4 1 1
9
2 2 4 4 4 7 7 7 7

3
10
9

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.