import sys
sys.setrecursionlimit(10**6)
N,Q = map(int,input().split())
lsg = [[] for i in range(N)]
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1 
    b -= 1
    lsg[a].append(b)
    lsg[b].append(a)
lsq = [tuple(map(int,input().split())) for i in range(Q)]

lsc = [1]*(N)
def dfs(k,p):
    for j in lsg[k]:
        if j == p:
            continue
        lsc[k] += dfs(j,k)
    return lsc[k]
dfs(0,-1)

ans = 0
for i in range(Q):
    p,x = lsq[i]
    p -= 1
    ans += lsc[p]*x
    print(ans)