#include <bits/stdc++.h>
using namespace std;

int tmp[105];
int dp[105][100005];
vector<int> ki[100005];

int dfs(int n,int p) {
    int res = 0;
    for(int i = 0; i < ki[n].size(); i++) {
        if(ki[n][i] == p) {
            continue;
        }
        res += dfs(ki[n][i],n);
    }
    if(res == 0) {
        tmp[n] = 1;
        return 1;
    }
    else {
        tmp[n] = res;
        return res;
    }
}

int main() {
    int N,K;
    cin >> N >> K;
    vector<int>a(N-1),b(N-1),c(N-1);
    for(int i = 0; i < N-1; i++) {
        cin >> a[i] >> b[i] >> c[i];
        a[i]--;
        b[i]--;
        ki[a[i]].push_back(b[i]);
        ki[b[i]].push_back(a[i]);
    }
    dfs(0,-1);
    int sum = 0;
    for(int i = 0; i < N-1; i++) {
        int cost = min(tmp[a[i]],tmp[b[i]])*c[i];
        sum += cost;
        for(int j = 0; j <= K; j++) {
            dp[i+1][j] = max(dp[i+1][j],dp[i][j]);
            if(j+c[i] <= K) {
                dp[i+1][j+c[i]] = max(dp[i+1][j+c[i]],dp[i][j]+cost);
            }
        }
    }
    int ans = 0;
    for(int i = 0; i <= K; i++) {
        ans = max(ans,dp[N-1][i]);
    }
    cout << sum+ans << endl;
}