import sys
sys.setrecursionlimit(10**9)
N,Q=map(int,input().split())
G=[[] for _ in range(N)]
for i in range(N-1):
  a,b=map(lambda x:int(x)-1,input().split())
  G[a].append(b)
  G[b].append(a)
seen=[False]*N
subtree_size=[1]*N
def dfs(G,v,p=-1):
  seen[v]=True 
  for nextv in G[v]:
    if nextv!=p:
      dfs(G,nextv,v)
  for c in G[v]:
    if c!=p:
      subtree_size[v]+=subtree_size[c]
dfs(G,0)
ans=0
for i in range(Q):
  p,x=map(int,input().split())
  ans+=x*subtree_size[p-1]
  print(ans)