#include <iostream>
#include <vector>
#include <algorithm>
#define int long long
#define rep(i, n) for(i = 0; i < n; i++)
using namespace std;

int n, k;
int from[100], to[100], cst[100];
vector<int> et[100];
vector<int> ec[100];
int chnum[100];
int parent[100];

int dfs(int p, int v) {
	parent[v] = p;
	if (et[v].size() == 1 && p != -1) return chnum[v] = 1;
	
	int i;
	int ret = 0;
	rep(i, et[v].size()) {
		int nv = et[v][i];
		if (nv == p) continue;
		ret += dfs(v, nv);
	}
	return chnum[v] = ret;
}

int dfs2(int p, int v) {
	if (et[v].size() == 1 && p != -1) { return 0; }
	
	int i;
	int ret = 0;
	rep(i, et[v].size()) {
		int nv = et[v][i];
		if (nv == p) continue;
		ret += dfs2(v, nv) + ec[v][i] * chnum[nv];
	}
	return ret;
}

int dp[101][100001];

signed main() {
	int i, j;
	
	cin >> n >> k;
	rep(i, n - 1) {
		int a, b, c;
		cin >> a >> b >> c;
		a--; b--;
		from[i] = a; to[i] = b; cst[i] = c;
		et[a].push_back(b);
		et[b].push_back(a);
		ec[a].push_back(c);
		ec[b].push_back(c);
	}
	
	dfs(-1, 0);
	
	vector<int> weight(n - 1), value(n - 1);
	rep(i, n - 1) {
		weight[i] = cst[i];
		value[i] = min(chnum[from[i]], chnum[to[i]]) * cst[i];
		//cout << weight[i] << ", " << value[i] << endl;
	}
	
	int INF = 1e+15;
	rep(i, n) rep(j, k + 1) dp[i][j] = -INF;
	
	dp[0][0] = 0;
	rep(i, n - 1) {
		rep(j, k + 1) {
			dp[i + 1][j] = max(dp[i + 1][j], dp[i][j]);
			if (j + weight[i] <= k) {
				dp[i + 1][j + weight[i]] = max(dp[i + 1][j + weight[i]], dp[i][j] + value[i]);
			}
		}
	}
	
	int ans = -INF;
	rep(i, k + 1) ans = max(ans, dp[n - 1][i]);
	
	int ans2 = dfs2(-1, 0);
	
	cout << ans + ans2 << endl;
	return 0;
}