from collections import deque

n,k = map(int,input().split())
e = [[] for i in range(n)]
cand = []
for i in range(n-1):
    a,b,c = map(int,input().split())
    a -= 1
    b -= 1
    e[a].append((b,c,i))
    e[b].append((a,c,i))
    cand.append((c,i))
count = [0]*n
def dfs(x,p,ind):
    num = 0
    leaf = 1
    for nex,c,i in e[x]:
        if nex == p:
            continue
        leaf = 0
        num += dfs(nex,x,i)
        
    if leaf:
        num = 1
    count[ind] += num
    return num

dfs(0,-1,n-1)

base = 0
for i in range(n-1):
    base += cand[i][0]*count[i]

dp = [0]*(k+1)
for i in range(n-1):
    c = cand[i][0]
    num = count[i]
    for j in range(k+1)[::-1]:
        if j+c <= k:
            dp[j+c] = max(dp[j+c],dp[j]+num*c)
print(base+dp[-1])