import times, strutils, sequtils, math, algorithm, tables, sets, lists, intsets
import critbits, future, strformat, deques
template `max=`(x,y) = x = max(x,y)
template `min=`(x,y) = x = min(x,y)
template `mod=`(x,y) = x = x mod y
template scan2 = (scan(), scan())
template scan3 = (scan(), scan())
let read* = iterator: string {.closure.} =
    while true: (for s in stdin.readLine.split: yield s)
proc scan(): int = read().parseInt
proc scanf(): float = read().parseFloat
proc toInt(c:char): int =
    return int(c) - int('0')




proc solve()=
  var
    n = scan()
    k = scan()
    es = newseqwith(n,newseq[int]())
    cost = newseqwith(n,newseq[int]())
    esu = newseqwith(n,newseq[int]())
    fp = newseqwith(n,false)
  for i in 0..<n-1:
    var
      (a,b,c)=(scan()-1,scan()-1,scan())
    es[a].add(b)
    es[b].add(a)

    cost[a].add(c)
    cost[b].add(c)
    esu[a].add(0)
    esu[b].add(0)
  proc dfs(par,p:int):int=
    if es[p].len==1 and es[p][0]==par:
      return 1
    for idx, nxt in es[p]:
      if nxt == par:continue
      var t = dfs(p,nxt)
      esu[p][idx]=t
      result+=t
  discard dfs(-1,0)
  #echo esu.join("\n")
  # 各辺の使用回数を計算
  var
    edge = newseq[int]()
    score = newseq[int]()
    base = 0
  for p in 0..<n:
    for (c,m) in zip(cost[p],esu[p]):
      if m!=0:
        base+=c*m
        edge.add(c)
        score.add(m*c)
  #echo edge
  #echo score
  var
    m = edge.len
    dp = newseqwith(m+1,newseqwith(k+1,0))
  # dp[i][j] := i個目の辺まで見たときに選んだ辺の総和がjであるときのスコアの最大値
  for i in 1..m:
    for j in 0..k:
      if j - edge[i-1]>=0:
        dp[i][j] = max(dp[i][j-edge[i-1]]+score[i-1],dp[i-1][j])
      else:
        dp[i][j] = dp[i-1][j]
  echo dp[m].max() + base


  

    


solve()