import sys
input = sys.stdin.readline
N, Q = map(int, input().split())
e = [[] for _ in range(N + 1)]
for _ in range(N - 1):
  u, v = map(int, input().split())
  e[u].append(v)
  e[v].append(u)

s = [1]
vis = [0] * (N + 1)
parent = [0] * (N + 1)
vis[1] = 1
order = []
while len(s):
  x = s.pop()
  order.append(x)
  for y in e[x]:
    if vis[y]: continue
    parent[y] = x
    vis[y] = 1
    s.append(y)

size = [1] * (N + 1)
order.reverse()
for y in order[: -1]:
  x = parent[y]
  size[x] += size[y]

res = 0
for _ in range(Q):
  x, v = map(int, input().split())
  res += size[x] * v
  print(res)