from collections import deque
n,Q = map(int,input().split())
e = [[] for i in range(n)]
for _ in range(n-1):
    a,b = [int(x)-1 for x in input().split()]
    e[a].append(b)
    e[b].append(a)

size = [1]*n

q = deque([0])
dis = [n]*n
dis[0] = 0
topo = []
while q:
    now = q.pop()
    topo.append(now)
    for nex in e[now]:
        if dis[nex] > dis[now]+1:
            q.append(nex)
            dis[nex] = dis[now]+1

for now in topo[::-1]:
    for nex in e[now]:
        if dis[nex] > dis[now]:
            size[now] += size[nex]

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