#include <iostream>
#include <vector>
#include <utility>
using namespace std;
using pii = pair<int, int>;
using Graph = vector<vector<pii>>;

int leaf[110], edge[110];

Graph G(110);

void dfs(int cur, int par) {
    if (int(G[cur].size())==1&&cur!=1) leaf[cur]=1;
    
    for (auto [dst, w]: G[cur]) {
        if (dst == par) continue;
        edge[dst]=w;
        dfs(dst, cur);
        leaf[cur]+=leaf[dst];
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, K; cin>>N>>K;
    for (int i=0;i<N-1;i++){
        int A, B, C; cin>>A>>B>>C;
        G[A].push_back({B, C});
        G[B].push_back({A, C});
    }
    dfs(1, -1);
    
    
    int base = 0;
    for (int i=2;i<=N;i++) base += leaf[i]*edge[i];
    
    vector<int> DP(K+1, 0);
    for (int i=2;i<=N;i++){
        for (int j=K;j>=edge[i];j--) DP[j] = max(DP[j], DP[j-edge[i]]+leaf[i]*edge[i]);
    }
    cout << base+DP[K] << "\n";
    return 0;
}