import sys
input = sys.stdin.readline

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)
size = [1] * N
st = [(0, -1, 0)]
while st:
    v, p, t = st.pop()
    if t == 0:
        st.append((v, p, 1))
        for c in G[v]:
            if c != p:
                st.append((c, v, 0))
    else:
        for c in G[v]:
            if c != p:
                size[v] += size[c]
ans = 0
for _ in range(Q):
    p, x = map(int, input().split())
    p -= 1
    ans += size[p] * x
    print(ans)