import sys
sys.setrecursionlimit(10 ** 6)
n, q = map(int, input().split())
G = [[] for i 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)
dp = [0] * n
def dfs(prev, cur):
    res = 1
    for nex in G[cur]:
        if nex != prev:
            res += dfs(cur, nex)
    dp[cur] = res
    return res
ans = 0
dfs(-1, 0)
for _ in range(q):
    p, x = map(int, input().split())
    ans += x * dp[p - 1]
    print(ans)