import sys
sys.setrecursionlimit(10**6)

n,q=map(int,input().split())
node=[[]for i in range(n)]
for i in range(n-1):
	a,b=map(int,input().split())
	node[a-1].append(b-1)
	node[b-1].append(a-1)

cnt=[0]*n
visited=[0]*n
visited[0]=1
def dfs(x):
	now=1
	for y in node[x]:
		if visited[y]==0:
			visited[y]=1
			now+=dfs(y)
	cnt[x]=now
	return now

dfs(0)

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