import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**5+10)
from collections import *

def dfs(v, pv=-1):
    for nv in G[v]:
        if nv==pv:
            continue
        
        dfs(nv, v)
        num[v] += num[nv]

N, Q = map(int, input().split())
G = [[] for _ in range(N)]

for _ in range(N-1):
    a, b = map(int, input().split())
    G[a-1].append(b-1)
    G[b-1].append(a-1)

num = [1]*N
dfs(0)
ans = 0

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