import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {
	static List<List<Hen>> list;

	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int k = sc.nextInt();
		list = new ArrayList<>(n);
		for (int i = 0; i < n; i++) {
			list.add(new ArrayList<>());
		}
		Hen[] arr = new Hen[n - 1];
		for (int i = 0; i < n - 1; i++) {
			Hen h = new Hen();
			h.a = sc.nextInt() - 1;
			h.b = sc.nextInt() - 1;
			h.c = sc.nextInt();
			list.get(h.a).add(h);
			list.get(h.b).add(h);
			arr[i] = h;
		}
		sc.close();

		dfs(0, -1);

		long[][] dp = new long[n][k + 1];
		for (int i = 0; i < n - 1; i++) {
			for (int j = 0; j <= k; j++) {
				dp[i + 1][j] = dp[i][j];
			}
			for (int j = 0; j <= k; j++) {
				int j2 = j + arr[i].c;
				if (j2 <= k) {
					dp[i + 1][j2] = Math.max(dp[i + 1][j2], dp[i][j] + arr[i].c * arr[i].d);
				} else {
					break;
				}
			}
		}

		long sum = 0;
		for (int i = 0; i < n - 1; i++) {
			sum += arr[i].c * arr[i].d;
		}

		long max = 0;
		for (int i = 0; i <= k; i++) {
			max = Math.max(max, dp[n - 1][i]);
		}
		System.out.println(sum + max);
	}

	static class Hen {
		int a, b, c, d;
	}

	static int dfs(int x, int p) {
		int ret = 0;
		if (list.get(x).size() == 1) {
			ret = 1;
		}
		for (Hen h : list.get(x)) {
			int nx = h.a;
			if (nx == x) {
				nx = h.b;
			}
			if (nx != p) {
				h.d = dfs(nx, x);
				ret += h.d;
			}
		}
		
		return ret;
	}
}