import sys
sys.setrecursionlimit(10 ** 9)

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

size = [0] * n
def dfs(pos, bpos):
    size[pos] = 1
    for npos in edges[pos]:
        if npos == bpos:
            continue
        dfs(npos, pos)
        size[pos] += size[npos]

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