n, q = map(int, input().split())

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


# graph and n is necessary
def dfs(start):
    par = [-1] * n
    depth = [-1] * n
    size = [0] * n
    stack = []
    stack.append(~start)
    stack.append(start)
    depth[start] = 0
    while stack:
        v = stack.pop()
        if v >= 0:
            d = depth[v]
            for u in graph[v]:
                if par[v] == u:
                    continue
                par[u] = v
                depth[u] = d + 1
                stack.append(~u)
                stack.append(u)
        else:
            a = ~v
            size[a] = 1
            for u in graph[a]:
                if u == par[a]:
                    continue
                size[a] += size[u]
    return size


size = dfs(0)

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