def main():
    setrecursionlimit(10 ** 6)

    n, q = map(int, input().split())
    adj = defaultdict(list)
    for _ in range(n - 1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        adj[a].append(b)
        adj[b].append(a)

    visited = [0] * n  # 0 = False
    subnodes = [0] * n

    def dfs(i):
        visited[i] = True
        res = 1
        for j in adj[i]:
            if visited[j]:
                continue
            res += dfs(j)
        subnodes[i] = res
        return res

    dfs(0)

    ans = []
    tmp = 0
    for _ in range(q):
        p, x = map(int, input().split())
        tmp += subnodes[p - 1] * x
        ans.append(tmp)
    print(*ans, sep='\n')


if __name__ == "__main__":
    main()