import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
sys.setrecursionlimit(10**7)
yes = lambda :print("yes");Yes = lambda :print("Yes")
no = lambda :print("no");No = lambda :print("No")
#######################################################################

n, Q = na()

g = [[] for i in range(n)]

for i in range(n-1):
    a,b = na()
    a-=1;b-=1
    g[a].append(b)
    g[b].append(a)

dp = [0 for i in range(n)]
dp[0] = 1
q = [0]
iki = [0]
G = [[] for i in range(n)]
while q:
    e = q.pop()
    for i in g[e]:
        if dp[i] == 0:
            dp[i] = 1
            G[e].append(i)
            q.append(i)
            iki.append(i)
dp = [1 for j in range(n)]
for i in iki[::-1]:
    for j in G[i]:
        dp[i]+=dp[j]
ans = 0
for i in range(Q):
    p,x = na()
    ans+=dp[p-1]*x
    print(ans)