import sys
sys.setrecursionlimit(10**8)
import pypyjit
pypyjit.set_param("max_unroll_recursion=-1")
input = sys.stdin.readline

N, K = map(int, input().split())
G = [list() for _ in range(N)]
for i in range(N-1):
    a, b, c = map(int, input().split())
    a-=1;b-=1
    G[a].append((b,c))
    G[b].append((a,c))

leaf = [0]*N
A = []
score = 0
def dfs(v, p):
    for next_v,_ in G[v]:
        if next_v == p:
            continue
        dfs(next_v, v)
    if len(G[v])==1 and v!=0:
        leaf[v] = 1
    else:
        leaf[v] = 0
        for c,cost in G[v]:
            if c== p:
                continue
            leaf[v] += leaf[c]
            A.append([cost,leaf[c]*cost])
            global score
            score += cost*leaf[c]

dfs(0,-1)
dp = [0]*(K+1)
for i in range(N-1):
    ndp = [0]*(K+1)
    w, v = A[i]
    for j in range(K+1):
        ndp[j] = max(ndp[j],dp[j])
        if j-w>=0:
            ndp[j] = max(ndp[j],dp[j-w]+v)
    dp = ndp
print(score+dp[-1])