import java.util.*;


public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int Q = scan.nextInt();
		Node[] nodes = new Node[N];
		for (int i = 0; i < N; i++) {
			nodes[i] = new Node();
		}
		int A, B;
		int tmp;
		for (int i = 1; i < N; i++) {
			A = scan.nextInt() - 1;
			B = scan.nextInt() - 1;
			nodes[A].chiledNum++;
			tmp = A;
			while (nodes[tmp].root != -1) {
				tmp = nodes[tmp].root;
				nodes[tmp].chiledNum++;
			}
			nodes[B].root = A;
		}

		long ans = 0;
		for (int i = 0; i < Q; i++) {
			A = scan.nextInt() - 1;
			B = scan.nextInt();
			ans += B * nodes[A].chiledNum;
			System.out.println(ans);
		}

	}
}

class Node {
	int root = -1;
	int chiledNum = 1;
}