def main():
    N, Q = map(int, input().split())
    tree = [set() for _ in range(N)]
    for _ in range(N-1):
        a, b = map(lambda n: int(n)-1, input().split())
        tree[a].add(b)
        tree[b].add(a)

    tree_size = [-1] * N

    stack = [(0, -1, 0)]
    while stack:
        cur, par, dir = stack.pop()
        match dir:
            case 1:
                tree_size[cur] = 1
                for n in tree[cur]:
                    if n == par:
                        continue
                    tree_size[cur] += tree_size[n]
            case 0:
                next_stack = []
                for n in tree[cur]:
                    if n == par:
                        continue
                    next_stack.append((n, cur, 0))
                stack.append((cur, par, 1))
                stack.extend(next_stack)
            case _:
                raise ValueError
    ans = 0
    for _ in range(Q):
        p, x = map(int, input().split())
        ans += tree_size[p-1] * x
        print(ans)


if __name__ == "__main__":
    main()