import sys
input=sys.stdin.buffer.readline
sys.setrecursionlimit(10**6)
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)
DP=[1]*N
def dfs(n,p):
  for i in range(len(G[n])):
    if G[n][i]!=p:
      DP[n]+=dfs(G[n][i],n)
  return DP[n]

dfs(0,-1)
ANS=0
for i in range(Q):
  p,x=map(int,input().split())
  ANS+=DP[p-1]*x
  print(ANS)