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)

src = 0
st = [~ src, src]
par = [None for _ in range(n)]
dp = [0 for _ in range(n)]
while len(st) > 0:
  cur = st.pop()
  if cur >= 0:
    for nxt in g[cur]:
      if nxt == par[cur]:
        continue
      par[nxt] = cur
      st.append(~ nxt)
      st.append(nxt)
  
  else:
    dp[~ cur] += 1
    if not par[~ cur] is None:
      dp[par[~ cur]] += dp[~ cur]

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