import sys
from collections import defaultdict
sys.setrecursionlimit(10**6)

n, q = map(int, input().split())
edge = defaultdict(list)
for _ in range(n - 1):
    a, b = map(int, input().split())
    a -= 1
    b -= 1
    edge[a].append(b)
    edge[b].append(a)

V = [0 for _ in range(n)]
def dfs(curr, prev):
    V[curr] += 1
    for np in edge[curr]:
        if np == prev:
            continue
        dfs(np, curr)
        V[curr] += V[np]
dfs(0, -1)

ans = 0
for _ in range(q):
    p, x = map(int, input().split())
    p -= 1
    ans += x * V[p]
    print(ans)