import sys
input = sys.stdin.readline
sys.setrecursionlimit(1000)

def dfs(v, pv, d):
    global ans, edges
    
    res = 0
    
    for nv, w in G[v]:
        if nv==pv:
            continue
        
        c = dfs(nv, v, d+w)
        edges.append((w, w*c))
        res += c
    
    if res==0:
        ans += d
        return 1
    
    return res

N, K = map(int, input().split())
G = [[] for _ in range(N)]

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

ans = 0
edges = []
dfs(0, -1, 0)
dp = [[0]*(K+1) for _ in range(N)]

for i in range(N-1):
    w, v = edges[i]
    
    for j in range(K+1):
        dp[i+1][j] = max(dp[i+1][j], dp[i][j])
        
        if j+w<=K:
            dp[i+1][j+w] = max(dp[i+1][j+w], dp[i][j]+v)

ans += max(dp[N-1])
print(ans)