write a go solution for Description:
You are given an array a of length n. Let cnt_x be the number of elements from the array which are equal to x. Let's also define f(x,y) as (cnt_x+cnt_y)*(x+y).

Also you are given m bad pairs (x_i,y_i). Note that if (x,y) is a bad pair, then (y,x) is also bad.

Your task is to find the maximum value of f(u,v) over all pairs (u,v), such that uneqv, that this pair is not bad, and also that u and v each occur in the array a. It is guaranteed that such a pair exists.

Input Format:
The first line contains a single integer t (1<=t<=10,000) — the number of test cases.

The first line of each test case contains two integers n and m (2<=n<=3*10^5, 0<=m<=3*10^5) — the length of the array and the number of bad pairs.

The second line of each test case contains n integers a_1,a_2,ldots,a_n (1<=a_i<=10^9) — elements of the array.

The i-th of the next m lines contains two integers x_i and y_i (1<=x_i<y_i<=10^9), which represent a bad pair. It is guaranteed that no bad pair occurs twice in the input. It is also guaranteed that cnt_x_i>0 and cnt_y_i>0.

It is guaranteed that for each test case there is a pair of integers (u,v), unev, that is not bad, and such that both of these numbers occur in a.

It is guaranteed that the total sum of n and the total sum of m don't exceed 3*10^5.

Output Format:
For each test case print a single integer — the answer to the problem.

Note:
In the first test case 3, 6, 7 occur in the array.

- f(3,6)=(cnt_3+cnt_6)*(3+6)=(3+2)*(3+6)=45. But (3,6) is bad so we ignore it.
- f(3,7)=(cnt_3+cnt_7)*(3+7)=(3+1)*(3+7)=40.
- f(6,7)=(cnt_6+cnt_7)*(6+7)=(2+1)*(6+7)=39.

The answer to the problem is max(40,39)=40.. Output only the code with no comments, explanation, or additional text.