import sys
from collections import defaultdict, Counter, deque
from itertools import permutations, combinations, product, combinations_with_replacement, groupby, accumulate
import operator
from math import sqrt, gcd, factorial
#from math import isqrt, prod, comb  #python3.8用(notpypy)
#from bisect import bisect_left, bisect_right
#from functools import lru_cache, reduce
#from heapq import heappush, heappop, heapify, heappushpop, heapreplace
#import numpy as np
#import networkx as nx
#from networkx.utils import UnionFind
#from numba import njit, b1, i1, i4, i8, f8
#numba例 @njit(i1(i4[:], i8[:, :]),cache=True) 引数i4配列、i8 2次元配列,戻り値i1
#from scipy.sparse import csr_matrix
#from scipy.sparse.csgraph import shortest_path, floyd_warshall, dijkstra, bellman_ford, johnson, NegativeCycleError, maximum_bipartite_matching, maximum_flow, minimum_spanning_tree
def input(): return sys.stdin.readline().rstrip()
def divceil(n, k): return 1+(n-1)//k  # n/kの切り上げを返す
def yn(hantei, yes='Yes', no='No'): print(yes if hantei else no)


def main():
    """
    グラフが隣接辺で与えられる場合
    """
    mod = 10**9+7
    mod2 = 998244353
    n,q=map(int, input().split())

    graph = [[] for _ in range(n)]

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

    mother = [[] for _ in range(n)]
    dp = [1]*n
    # print(dp)
    visited = [False]*n
    visited[0] = True

    d = deque()
    d.append(0)

    def merge(a, b):
        return (a+b)

    while d:
        v = d[-1]
        if graph[v] == []:  # 帰りがけ
            for m in mother[v]:
                dp[v] = merge(dp[v], dp[m])
            d.pop()
        else:  # 行きがけ
            i = graph[v].pop()
            if visited[i]:
                continue
            visited[i] = True
            d.append(i)
            mother[v].append(i)
    ans=0
    for i in range(q):
        p,x=map(int, input().split())
        p-=1
        ans+=dp[p]*x
        print(ans)



if __name__ == '__main__':
    main()