N, K = gets.split.map(&:to_i)
E = Hash.new { |h, k| h[k] = [] }
C = Array.new(N + 1) { Array.new(N + 1, 0) }
L = []

(N - 1).times do
  a, b, c = gets.split.map(&:to_i)

  if a < b
    L << [a, b, c]
    E[a] << [b, c]
    E[b] << [a, c]
  else
    L << [b, a, c]
    E[a] << [b, c]
    E[b] << [a, c]
  end
end

def dfs(v, parent = -1)
  val = 0

  E[v].each do |u, c|
    next if u == parent

    a = dfs(u, v)
    C[v][u] = C[u][v] = a
    val += a
  end

  [1, val].max
end

dfs(1)

dp = Hash.new(0)
dp[0] = L.map { |u, v, c| C[u][v] * c }.sum

L.each do |u, v, c|
  temp = dp.dup

  dp.each do |k, val|
    nk = k + c
    nc = val + C[u][v] * c
    next if nk > K
    next if temp[nk] >= nc

    temp[nk] = nc
  end

  dp = temp
end

pp dp.values.max