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

ch=[0]*n
def rec(v, p= -1):
    ret = 1
    for nv in g[v]:
        if nv==p:continue
        ret += rec(nv, v)
    ch[v] = ret
    return ret
rec(0)
ans=0
for _ in range(q):
    p,x=map(int,input().split())
    p -= 1
    ans += ch[p] * x
    print(ans)