#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	int N, K;
	cin >> N >> K;
	vector<vector<pii>> g(N);
	vector<int> A(N - 1), B(N - 1), C(N - 1);
	REP(i, N - 1) {
		scanf("%d %d %d", &A[i], &B[i], &C[i]);
		--A[i]; --B[i];
		g[A[i]].emplace_back(B[i], i);
		g[B[i]].emplace_back(A[i], i);
	}
	auto D = C;
	
	auto dfs = [&](auto self, int u, int p, int pedge) -> int {
		int leaf = 0;
		for (auto [v, eidx] : g[u]) {
			if (v == p) continue;
			leaf += self(self, v, u, eidx);
		}
		if (leaf == 0) leaf = 1;
		if (p != -1) D[pedge] *= leaf;
		return leaf;
	};
	dfs(dfs, 0, -1, -1);
	
	int ans = 0;
	REP(i, N) {
		auto dfs2 = [&](auto self, int u, int p, int c, int d) -> void {
			chmax(ans, d);
			for (auto [v, eidx] : g[u]) {
				if (v == p) continue;
				const int nexc = c + C[eidx];
				if (nexc > K) break;
				self(self, v, u, nexc, d + D[eidx]);
			}
		};
		dfs2(dfs2, i, -1, 0, 0);
	}
	ans += accumulate(ALL(D), 0);
	cout << ans << endl;
}