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-=1
  b-=1
  g[a].append(b)
  g[b].append(a)
s=[0]*n
def dfs(now,before):
  s[now]=1
  for next in g[now]:
    if next==before:
      continue
    dfs(next,now)
    s[now]+=s[next]
dfs(0,-1)
ans=0
for _ in range(q):
  p,x=map(int,input().split())
  p-=1
  ans+=s[p]*x
  print(ans)