N,Q = map(int,input().split())
def f(n):
    return int(n) - 1
ab = [list(map(f,input().split( ))) for _ in range(N-1)]
import sys
sys.setrecursionlimit(10**8)
e = [[] for _ in range(N)]
for i in range(N-1):
    a,b = ab[i]
    e[a].append(b)
    e[b].append(a)
d = [0 for _ in range(N)]
def dfs(n):
    d[n] += 1
    for i in e[n]:
        if d[i] != 0:
            continue
        dfs(i)
        d[n] += d[i]
dfs(0)
sum = 0

for i in range(Q):
    p,x = map(int,input().split())
    sum += d[p-1]*x
    print(sum)