def tree_dfs(g, root=0):
    s = [root]
    d = [1] * len(g)
    order = []
    while s:
        p = s.pop()
        d[p] = 0
        order.append(p)
        for node in g[p]:
            if d[node]:
                s.append(node)
    return order

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

order = tree_dfs(g)
d = [0] * n
d[0] = 0
for v in order[::-1]:
    d[v] = 1
    for node in g[v]:
        d[v] += d[node]
ans = 0
for i in range(q):
    p, x = map(int, input().split())
    ans += d[p - 1] * x
    print(ans)