N, Q = gets.split.map(&:to_i)
graph = Array.new(N) { [] }
(N - 1).times do
    u, v = gets.split.map(&:to_i)
    graph[u - 1] << v - 1
    graph[v - 1] << u - 1
end

weight = Array.new(N, 1)
visited = Array.new(N, false)
dfs = ->(u) {
    visited[u] = true
    graph[u].each do |v|
        next if visited[v]
        dfs[v]
        weight[u] += weight[v]
    end
}
dfs[0]

sum = 0
Q.times do
    v, c = gets.split.map(&:to_i)
    sum += weight[v - 1] * c
    puts sum
end