import sys

sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


N,Q = MI()
Graph = [[] for _ in range(N+1)]
for _ in range(N-1):
    a,b = MI()
    Graph[a].append(b)
    Graph[b].append(a)


subtree = [0]*(N+1)


def dfs(i,par):
    if subtree[i] != 0:
        return subtree[i]
    res = 1
    for j in Graph[i]:
        if j == par:
            continue
        res += dfs(j,i)
    subtree[i] = res
    return res


dfs(1,0)

cur = 0
for _ in range(Q):
    p,x = MI()
    cur += x*subtree[p]
    print(cur)