#include <bits/stdc++.h>
using namespace std;
const int N = 105;
int n, q, x, y, z, dp[2 * N][N], bz[N][N];
bool zg[N];
vector<vector<int> > bian(N);
void dfs(int x) {
    int g = 0, x123, y;
    for (int i = 0; i < bian[x].size(); i++) {
        if (zg[bian[x][i]] == 0) {
            zg[bian[x][i]] = 1;
            dfs(bian[x][i]);
            if (g == 0) {
                g++;
                x123 = bian[x][i];
            } else {
                g++;
                y = bian[x][i];
            }
        }
    }
    if (g == 0)
        return;
    // cout<<x<<" "<<x123<<" "<<y<<"\n";
    for (int i = 1; i <= q; i++) {
        dp[x][i] = max(dp[x][i], dp[x123][i - 1] + bz[x][x123]);
    }
    if (g == 1)
        return;
    for (int i = 1; i <= q; i++) {
        dp[x][i] = max(dp[x][i], dp[y][i - 1] + bz[x][y]);
    }
    for (int i = q; i >= 0; i--) {
        for (int j = q; j >= 0; j--) {
            dp[x][i + j + 2] = max(dp[x][i + j + 2], dp[x123][i] + dp[y][j] + bz[x][x123] + bz[x][y]);
        }
    }
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    cin >> n >> q;
    zg[1] = 1;
    for (int i = 1; i < n; i++) {
        cin >> x >> y >> z;
        bz[x][y] = z;
        bz[y][x] = z;
        bian[x].push_back(y);
        bian[y].push_back(x);
    }
    dfs(1);
    cout << dp[1][q] << "\n";
}