import sys
INF = float('inf')
#10**20,2**63,float('inf')
MOD = 10**9 + 7
MOD2 = 998244353
#from collections import defaultdict
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LC(): return list(input())
def IC(): return [int(c) for c in input()]
def MI(): return map(int, sys.stdin.readline().split())
N,Q = MI()
Graph = [[] for _ in range(N+1)]
for _ in range(N-1):
    A,B = MI()
    Graph[A].append(B)
    Graph[B].append(A)
sys.setrecursionlimit(10 ** 6)#再帰関数ではコメントにしないこと！！
DP = [0]*(N+1)
Seen = [False]*(N+1)
def dfs(now):
    Seen[now] = True
    DP[now] = 1
    #→nowで初めてたどり着いたときに行う処理はここで
    for next in Graph[now]:
        if not Seen[next]:
            dfs(next)
            DP[now] += DP[next]
            # next→now:戻る時に行う処理はここで
    # now←で全ての探索可ノードを終えたときに行う処理はここで
dfs(1)#根は1
#print(DP)
Ans = 0
for _ in range(Q):
    P,X = MI()
    Ans += DP[P]*X
    print(Ans)