import sys
sys.setrecursionlimit(10 ** 6)
N,Q = map(int,input().split())
G = [[] for i in range(N)]

for _ in range(N - 1):
    a,b = map(int,input().split())
    G[a - 1].append(b - 1)
    G[b - 1].append(a - 1)
    
cnt = [0] * N # 自分を含む子の数
def dfs(v, p):
    c = 1
    for child in G[v]:
        if child == p:
            continue
        c += dfs(child, v)
    cnt[v] = c
    return c
    
dfs(0, -1)
        
ans = 0
for _ in range(Q):
    p,x = map(int,input().split())
    ans += cnt[p - 1] * x
    print(ans)