import sys
import io, os
input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

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

s = []
order = []
par = [-1]*n
s.append(0)
while s:
    v = s.pop()
    order.append(v)
    for u in g[v]:
        if par[v] == u:
            continue
        par[u] = v
        s.append(u)
order.reverse()
C = [1]*n
for v in order:
    if par[v] != -1:
        C[par[v]] += C[v]

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