write a go solution for Description:
You are given a tree consisting of n vertices. Recall that a tree is an undirected connected acyclic graph. The given tree is rooted at the vertex 1.

You have to process q queries. In each query, you are given a vertex of the tree v and an integer k.

To process a query, you may delete any vertices from the tree in any order, except for the root and the vertex v. When a vertex is deleted, its children become the children of its parent. You have to process a query in such a way that maximizes the value of c(v)-m*k (where c(v) is the resulting number of children of the vertex v, and m is the number of vertices you have deleted). Print the maximum possible value you can obtain.

The queries are independent: the changes you make to the tree while processing a query don't affect the tree in other queries.

Input Format:
The first line contains one integer n (1<=n<=2*10^5) — the number of vertices in the tree.

Then n-1 lines follow, the i-th of them contains two integers x_i and y_i (1<=x_i,y_i<=n; x_iney_i) — the endpoints of the i-th edge. These edges form a tree.

The next line contains one integer q (1<=q<=2*10^5) — the number of queries.

Then q lines follow, the j-th of them contains two integers v_j and k_j (1<=v_j<=n; 0<=k_j<=2*10^5) — the parameters of the j-th query.

Output Format:
For each query, print one integer — the maximum value of c(v)-m*k you can achieve.

Note:
The tree in the first example is shown in the following picture:

Answers to the queries are obtained as follows:

1. v=1,k=0: you can delete vertices 7 and 3, so the vertex 1 has 5 children (vertices 2, 4, 5, 6, and 8), and the score is 5-2*0=5;
2. v=1,k=2: you can delete the vertex 7, so the vertex 1 has 4 children (vertices 3, 4, 5, and 6), and the score is 4-1*2=2.
3. v=1,k=3: you shouldn't delete any vertices, so the vertex 1 has only one child (vertex 7), and the score is 1-0*3=1;
4. v=7,k=1: you can delete the vertex 3, so the vertex 7 has 5 children (vertices 2, 4, 5, 6, and 8), and the score is 5-1*1=4;
5. v=5,k=0: no matter what you do, the vertex 5 will have no children, so the score is 0;
6. v=7,k=200000: you shouldn't delete any vertices, so the vertex 7 has 4 children (vertices 3, 4, 5, and 6), and the score is 4-0*200000=4.. Output only the code with no comments, explanation, or additional text.