package yukicoder;

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

public class No1488 {
	
	private static class Peek {
		List<Integer> edge;
		List<Integer[]> peeks;
		public Peek() {
			edge = new ArrayList<Integer>();
			peeks = new ArrayList<Integer[]>();
		}
	}
	
	private static class Queue {
		int i;
		List<Integer> edge;
		public Queue(int i) {
			this.i = i;
			this.edge = new ArrayList<Integer>();
		}
		public Queue(int i, List<Integer> edge, int c) {
			this.i = i;
			this.edge = new ArrayList<Integer>(edge);
			this.edge.add(c);
		}
	}

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int K = scan.nextInt();
		List<Peek> v = new ArrayList<Peek>();
		for (int i=0; i < N; i++) {
			v.add(new Peek());
		}
		int[] weight = new int[N-1];
		for (int i=0; i < N-1; i++) {
			int a = scan.nextInt() - 1;
			int b = scan.nextInt() - 1;
			int c = scan.nextInt();
			v.get(a).peeks.add(new Integer[] {b, i});
			v.get(b).peeks.add(new Integer[] {a, i});
			weight[i] = c;
		}
		scan.close();
		List<Queue> q = new ArrayList<Queue>();
		q.add(new Queue(0));
		int[] e = new int[N-1];
		while (q.size() > 0) {
			Queue qi = q.remove(0);
			v.get(qi.i).edge = qi.edge;
			boolean cnt = true;
			for (Integer[] j : v.get(qi.i).peeks) {
				if (j[0] == 0 || v.get(j[0]).edge.size() > 0) {
					continue;
				}
				cnt = false;
				q.add(new Queue(j[0], qi.edge, j[1]));
			}
			if (cnt) {
				for (int j : qi.edge) {
					e[j]++;
				}
			}
		}
		int[][] dp = new int[N][K+1];
		int val = 0;
		for (int i=0; i < N-1; i++) {
			val += weight[i] * e[i];
			for (int w = 0; w <= K; w++) {
				if (w >= weight[i]) {
					dp[i+1][w] = Math.max(dp[i][w-weight[i]] + weight[i] * e[i], dp[i][w]);
				} else {
					dp[i+1][w] = dp[i][w];
				}
			}
		}
		System.out.println(dp[N-1][K]+val);
	}

}