import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)

N, Q = map(int, input().split())
G = [[] for _ in range(N)]
for _ in range(N-1):
    a, b = map(int, input().split())
    a -= 1
    b -= 1
    G[a].append(b)
    G[b].append(a)

par = [-1] * N
topo = []
que = [0]
while que:
    s = que.pop()
    topo.append(s)
    for t in G[s]:
        if t == par[s]:
            continue
        par[t] = s
        que.append(t)

sz = [1] * N
for s in topo[::-1][:-1]:
    p = par[s]
    sz[p] += sz[s]

ans = 0
for _ in range(Q):
    p, x = map(int, input().split())
    p -= 1
    ans += sz[p] * x
    print(ans)