"""

ナップザック問題やな
辺が99個しかない



"""

import sys
from sys import stdin
import math

ans = 0
elis = []

def dfs(v,p):

    global ans
    global elis

    vsum = 0
    if v != p and len(lis[v]) == 1:
        return 1
    
    for nex,cost in lis[v]:
        if nex != p:

            cat = dfs(nex,v)
            elis.append( (cost,cost*cat) )
            vsum += cat
            ans += cost * cat

    return vsum

N,K = map(int,stdin.readline().split())

lis = [ [] for i in range(N)]
for i in range(N-1):

    a,b,c = map(int,stdin.readline().split())
    a -= 1
    b -= 1

    lis[a].append( (b,c) )
    lis[b].append( (a,c) )

dfs(0,0)

dp = [0] * (K+1)
for cost,r in elis:
    for i in range(K-cost,-1,-1):
        dp[i+cost] = max(dp[i+cost],dp[i]+r)

print (ans + max(dp))