using System;
using System.Collections.Generic;
using static System.Console;
using System.Linq;

class yuki308
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NMap(int n) => Enumerable.Repeat<int>(0, n).Select(_ => NList).ToArray();
  
    static void Main()
    {
        var c = NList;
        var (n, q) = (c[0], c[1]);
        var map = NMap(n - 1);
        var queries = NMap(q);

        var tree = new List<int>[n];
        for (var i = 0; i < tree.Length; ++i) tree[i] = new List<int>();
        foreach (var edge in map)
        {
            tree[edge[0] - 1].Add(edge[1] - 1);
            tree[edge[1] - 1].Add(edge[0] - 1);
        }

        var cnum = new int[n];
        DFS(-1, 0, tree, cnum);

        var res = 0L;
        var rlist = new long[q];
        for (var i = 0; i < q; ++i)
        {
            res += (long)cnum[queries[i][0] - 1] * queries[i][1];
            rlist[i] = res;
        }
        WriteLine(string.Join("\n", rlist));
    }
    static int DFS(int prev, int cur, List<int>[] tree, int[] cnum)
    {
        var num = 1;
        foreach (var next in tree[cur])
        {
            if (prev == next) continue;
            num += DFS(cur, next, tree, cnum);
        }
        cnum[cur] = num;
        return num;
    }
}