#include <stdio.h>

typedef struct List {
	struct List *next;
	int v, cost;
} list;

void chmax(int* a, int b)
{
	if (*a < b) *a = b;
}

int main()
{
	int i, N, K, u, w, c;
	list *adj[101] = {}, e[201], *p;
	scanf("%d %d", &N, &K);
	for (i = 0; i < N - 1; i++) {
		scanf("%d %d %d", &u, &w, &c);
		e[i*2].v = w;
		e[i*2+1].v = u;
		e[i*2].cost = c;
		e[i*2+1].cost = c;
		e[i*2].next = adj[u];
		e[i*2+1].next = adj[w];
		adj[u] = &(e[i*2]);
		adj[w] = &(e[i*2+1]);
	}
	
	int par[101] = {}, depth[101], q[101], head, tail;
	par[1] = 1;
	depth[1] = 0;
	q[0] = 1;
	for (head = 0, tail = 1; head < tail; head++) {
		u = q[head];
		for (p = adj[u]; p != NULL; p = p->next) {
			w = p->v;
			if (par[w] == 0) {
				par[w] = u;
				depth[w] = depth[u] + p->cost;
				q[tail++] = w;
			}
		}
	}

	int leaf[101] = {}, weight[101], value[101], sum = 0;
	for (head--; head >= 0; head--) {
		u = q[head];
		for (p = adj[u]; p != NULL; p = p->next) {
			w = p->v;
			c = p->cost;
			if (w == par[u]) continue;
			leaf[u] += leaf[w];
			weight[w] = c;
			value[w] = leaf[w] * c;
		}
		if (leaf[u] == 0) {
			sum += depth[u];
			leaf[u] = 1;
		}
	}
	
	int ans = 0, dp[100001] = {};
	for (u = 2; u <= N; u++) {
		for (i = K; i >= weight[u]; i--) chmax(&(dp[i]), dp[i - weight[u]] + value[u]);
	}
	for (i = 0; i <= K; i++) chmax(&ans, dp[i]);
	printf("%d\n", ans + sum);
	fflush(stdout);
	return 0;
}