require 'tsort'

class Hash
  include TSort
  alias tsort_each_node each_key
  def tsort_each_child(node, &block)
    fetch(node).each(&block)
  end
end

N, Q = gets.split.map(&:to_i)
OE = Array.new(N + 1) { [] }
E = Hash.new
RE = Hash.new { |h, k| h[k] = [] }
1.upto(N) do |v|
  E[v] = []
end

(N - 1).times do
  a, b = gets.split.map(&:to_i)
  OE[a] << b
  OE[b] << a
end

visited = Array.new(N + 1, false)
queue = [1]
until queue.empty?
  v = queue.shift

  next if visited[v]
  visited[v] = true

  OE[v].each do |u|
    next if visited[u]

    E[v] << u
    RE[u] << v
    queue << u
  end
end

C = Array.new(N + 1, 0)
E.tsort.each do |v|
  C[v] += 1

  RE[v].each do |u|
    C[u] += C[v]
  end
end

ans = 0

Q.times do
  p, x = gets.split.map(&:to_i)
  ans += C[p] * x

  puts ans
end