n, k = map(int, input().split())
edges = [[] for _ in range(n)]
for _ in range(n - 1):
    a, b, c = map(int, input().split())
    a -= 1
    b -= 1
    edges[a].append((b, c))
    edges[b].append((a, c))
    
wv = []
ans = 0

def dfs(pos, bpos, cc):
    if len(edges[pos]) == 1:
        ret = 1
        if pos != 0:
            global ans
            ans += cc
        
    else:
        ret = 0
    for npos, c in edges[pos]:
        if npos == bpos:
            continue
        tmp = dfs(npos, pos, cc + c)
        wv.append((c, c * tmp))
        ret += tmp
    return ret
    
dfs(0, -1, 0)

dp = [0] * (k + 1)
for w, v in wv:
    for i in range(k, w - 1, -1):
        dp[i] = max(dp[i], dp[i - w] + v)
print(dp[-1] + ans)