N, K = gets.split.map(&:to_i)
graph = Array.new(N) { [] }
weight = []
(N - 1).times do
    a, b, c = gets.split.map(&:to_i)
    e = weight.size
    graph[a - 1] << [b - 1, e]
    graph[b - 1] << [a - 1, e]
    weight << c
end

value = [0] * (N - 1)
path = []
visited = [false] * N
dfs = ->(u) {
    visited[u] = true
    has_children = false
    graph[u].each do |(v, e)|
        next if visited[v]
        has_children = true
        path << e
        dfs[v]
        path.pop
    end
    unless has_children
      path.each do |e|
        value[e] += weight[e]
      end
    end
}
dfs[0]

dp = Array.new(K + 1, 0)
(0 ... N - 1).each do |i|
  dp2 = Array.new(K + 1, 0)
  (0 .. K).each do |w|
    v = dp[w]
    v = [v, dp[w - weight[i]] + value[i]].max if w >= weight[i]
    dp2[w] = v
  end
  dp = dp2
end

puts value.sum + dp[K]