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

node = [[0] * 2 for _ in range(N + 1)]
edge = []
score = 0
def tansaku(now = 1,parent = 0):
    global score
    node[now][0] = parent
    if now != 1 and len(G[now]) == 1:
        node[now][1] = 1
        return 1
    for v,c in G[now]:
        if v != parent:
            t = tansaku(v,now)
            node[now][1] += t
            edge.append((c,t))
            score += c * t
    return node[now][1]
tansaku()
dp = [[0] * (K + 1) for _ in range(N-1)]
dp[0][edge[0][0]] = edge[0][1] * edge[0][0]
for i in range(1,N-1):
    c,t = edge[i]
    for j in range(K + 1):
        dp[i][j] = dp[i-1][j]
        if j - c >= 0:
            if dp[i][j] < dp[i-1][j-c] + c * t:
                dp[i][j] = dp[i-1][j-c] + c * t
m = max(dp[N-2])
print(m + score)