import sys
sys.setrecursionlimit(10**6)
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)
subnode=[[] for _ in range(n)]
visit=[False]*n
def f(start):
    visit[start]=True
    num=1
    for i in g[start]:
        num+=f(i)
    subnode[start]=num
    return num
f(0)
ans=0
for _ in range(q):
    p,x=map(int,input().split())
    ans+=subnode[p-1]*x
    print(ans)