import sys
from sys import stdin

from collections import deque
def NC_Dij(lis,start):

    ret = [float("inf")] * len(lis)
    ret[start] = 0
    
    q = deque([start])
    plis = [i for i in range(len(lis))]

    while len(q) > 0:
        now = q.popleft()

        for nex in lis[now]:

            if ret[nex] > ret[now] + 1:
                ret[nex] = ret[now] + 1
                plis[nex] = now
                q.append(nex)

    return ret,plis

N,Q = map(int,stdin.readline().split())

lis = [ [] for i in range(N) ]

for i in range(N-1):
    a,b = map(int,stdin.readline().split())
    a -= 1
    b -= 1

    lis[a].append(b)
    lis[b].append(a)

dlis,plis = NC_Dij(lis,0)

di = [(dlis[i],i) for i in range(N)]
di.sort()
di.reverse()

c = [1] * N
#print (di,plis)

for td,v in di:
    if plis[v] != v:
        c[plis[v]] += c[v]

#print (c)

ANS = []
ans = 0

for i in range(Q):

    p,x = map(int,stdin.readline().split())
    p -= 1
    ans += c[p] * x
    ANS.append(str(ans))

print ("\n".join(ANS))