Example

Input

3 2
1 2 1
2 3 2
1 10 100


Output

320
#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(auto& (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define sar(a,n) cout<<#a<<":";rep(pachico,n)cout<<" "<<a[pachico];cout<<endl
#define svec(v) cout<<#v<<":";rep(pachico,v.size())cout<<" "<<v[pachico];cout<<endl
#define svecp(v) cout<<#v<<":";each(pachico,v)cout<<" {"<<pachico.first<<":"<<pachico.second<<"}";cout<<endl
#define sset(s) cout<<#s<<":";each(pachico,s)cout<<" "<<pachico;cout<<endl
#define smap(m) cout<<#m<<":";each(pachico,m)cout<<" {"<<pachico.first<<":"<<pachico.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int> P;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<P> vp;
typedef vector<string> vs;

const int MAX_N = 100005;

struct edge
{
    int to;
    ll cost;
};

vector<edge> G[MAX_N];

ll dfs(int u, int p, const ll w, vector<ll>& path)
{
    vector<ll> kp;
    each(e, G[u]){
        if(e.to != p){
            kp.pb(e.cost + dfs(e.to, u, w, path));
        }
    }
    if(len(kp) == 0) return 0;
    sort(all(kp),greater<ll>());
    srep(i,1,len(kp)){
        path.pb(w*kp[i]);
    }
    return kp[0];
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, m;
    cin >> n >> m;
    rep(i,n-1){
        int a,b,c;
        cin >> a >> b >> c;
        --a, --b;
        G[a].pb((edge){b,c}), G[b].pb((edge){a,c});
    }
    vl s(n);
    rep(i,n){
        cin >> s[i];
    }
    vector<ll> path;
    rep(i,n){
        path.pb(s[i] * dfs(i, -1, s[i], path));
    }
    sort(all(path),greater<ll>());
    cout << accumulate(path.begin(),path.begin()+min(m,len(path)),0LL) << "\n";
    return 0;
}
