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

dp = [0] * n
def dfs(u, p=-1):
    dp[u] = 1
    for v in to[u]:
        if v == p:
            continue
        dfs(v, u)
        dp[u] += dp[v]

dfs(0)
ans = 0

for _ in range(q):
    p, x = map(int, input().split())
    ans += dp[p - 1] * x
    print(ans)