import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

public class Main {
	static List<List<Integer>> list;
	static int[] dp;

	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int n = Integer.parseInt(sa[0]);
		int q = Integer.parseInt(sa[1]);
		list = new ArrayList<>(n);
		for (int i = 0; i < n; i++) {
			list.add(new ArrayList<>());
		}
		for (int i = 0; i < n - 1; i++) {
			sa = br.readLine().split(" ");
			int a = Integer.parseInt(sa[0]) - 1;
			int b = Integer.parseInt(sa[1]) - 1;
			list.get(a).add(b);
			list.get(b).add(a);
		}
		int[] p = new int[q];
		int[] x = new int[q];
		for (int i = 0; i < q; i++) {
			sa = br.readLine().split(" ");
			p[i] = Integer.parseInt(sa[0]) - 1;
			x[i] = Integer.parseInt(sa[1]);
		}
		br.close();

		dp = new int[n];
		dfs(0, -1);
		long ans = 0;
		PrintWriter pw = new PrintWriter(System.out);
		for (int i = 0; i < q; i++) {
			ans += (long) dp[p[i]] * x[i];
			pw.println(ans);
		}
		pw.flush();
	}

	static int dfs(int x, int p) {
		int ret = 1;
		for (int c : list.get(x)) {
			if (c != p) {
				ret += dfs(c, x);
			}
		}
		return dp[x] = ret;
	}
}