#include <bits/stdc++.h>
#pragma GCC optimize("O3")

#define fi first
#define se second
#define pb push_back

typedef long long ll;
#define int ll

using namespace std;

const int N = 3e5+100;
const int K = 66;

vector<pair<int, ll> > g[2*N];
vector<pair<int, ll> > g1[2*N][2];

pair<int, int> x[N];
int x0[N];
int n, k;

int index(int x, int r)
{
    return x*2+r;
}

void add_edge(int x1, int r1, int x2, int r2)
{
//    g[index(x1, r1)].pb({index(x2, r2), 2ll * x[x1].se * abs(x[x1].fi - x[x2].fi) + (r1 != r2)});
    g1[x1][ (x[x1].fi < x[x2].fi) ? 0 : 1].pb({x2, x[x1].se * abs(x[x1].fi - x[x2].fi)});
}

void add_edge(int x1, int x2)
{
    int r2 = (x[x1].fi > x[x2].fi);
    for (int r1=0; r1<2; r1++)
        add_edge(x1, r1, x2, r2);
}

ll DIST[2*N];

void jump(int tp)
{
//    for (int i=0; i<n; i++)
//        cout<<DIST[i]<<" ";
//    cout<<"\n";
    if (tp == 0)
    {
        for (int i=0; i<n; i++)
            for (auto [j, l] : g1[i][tp])
                DIST[j] = min(DIST[j], DIST[i] + l);
    }
    else
    {
        for (int i=n-1; i>=0; i--)
            for (auto [j, l] : g1[i][tp])
                DIST[j] = min(DIST[j], DIST[i] + l);
    }
//    cout<<" => \n";
//    for (int i=0; i<n; i++)
//        cout<<DIST[i]<<" ";
//    cout<<"\n";
}

int SOLVE(int a, int b, int k)
{
    for (int i=0; i<n; i++)
        DIST[i] = 1e18;
    DIST[a] = 0;
    for (int i=0; i<k; i++)
        jump(i%2);
    int ans = DIST[b];
    for (int i=0; i<n; i++)
        DIST[i] = 1e18;
    DIST[a] = 0;
    for (int i=0; i<k; i++)
        jump(1-i%2);
    return min<int>(ans, DIST[b]);
}

ll dijkstra(int a, int b, int k)
{
    static ll cur[2*N],nxt[2*N];
    const ll INF=1e18;
    for(int i=0;i<=a;i++)
        cur[i]=nxt[i]=INF;
    cur[a]=0;
    for(int level=0;level<k;level++) {
        priority_queue<pair<ll, int>> pq;
        for(int i=0;i<=a;i++)
            cur[i]=min(cur[i],nxt[i]),
            pq.emplace(-cur[i], i),
            nxt[i]=INF;
        while (!pq.empty()) {
            auto [d, v] = pq.top();
            pq.pop();
            d = -d;
            if (d != cur[v])
                continue;
            for (auto [to, w]: g[v])
                if(w%2)
                    nxt[to]=min(nxt[to],d+w/2);
                else if (cur[to] > d + w/2)
                    cur[to] = d + w/2,
                    pq.emplace(-cur[to], to);
        }
//        for(int i=0;i<=a;i++)
//            cout<<level<<" "<<i<<" -> "<<cur[i]<<"\n";
    }
    return min(cur[2*b],cur[2*b+1]);
}

int T;
mt19937 rng(time(0));
void solve()
{
//    n = 300000/T;
//    k = 3e5;
    cin>>n>>k;
    k = min(k+1, K);
    for (int i=0; i<=2*n; i++)
        g[i].clear();
    for (int i=0; i<=n; i++)
        g1[i][0].clear(), g1[i][1].clear();
    vector<pair<int, int> > v;
    for (int i=0; i<n; i++)
        cin>>x[i].fi;
    for (int i=0; i<n; i++)
        cin>>x[i].se;
//    for (int i=0; i<n; i++)
//    {
//        x[i].fi = i;
//        x[i].se = rng()%int(1e9)+1;
//    }

    for (int i=0; i<n; i++)
        x0[i]=x[i].fi;
    sort(x, x+n);
    int a=-1, b=-1;
    for (int i=0; i<n; i++)
        if (x[i].fi == x0[0])
            a = i;
        else if (x[i].fi == x0[n-1])
            b = i;
    for (int i=0; i<n; i++)
        v.pb({x[i].se, i});

    sort(v.begin(), v.end());
    set<pair<int, int> > xs;
    for (auto [s, i] : v)
    {
//        if (i!=a)
        {
            auto it = xs.lower_bound({x[i].fi, 0});
            if (it != xs.end())
                if (it->se != b)
                {
//                    cout<<"F "<<i<<" "<<it->se<<"\n";
                    add_edge(i,  it->se);
                }
            if (it != xs.begin())
                if (prev(it)->se != b)
                {
//                    cout<<"B "<<i<<" "<<prev(it)->se<<"\n";
                    add_edge(i, prev(it)->se);
                }
        }
        xs.insert({x[i].fi, i});
    }
//    for (int i=0; i<n; i++)
//        if (i != a) add_edge(a, i);
    for (int i=0; i<n; i++)
        if (i != b) add_edge(i, b);
//    g[2*n].pb({index(a, 0), 0});
//    g[2*n].pb({index(a, 1), 0});

    cout<<SOLVE(a, b, k)<<"\n";
//    cout<<dijkstra(2*n, b, k)<<"\n";
}

main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    srand(time(0));

    cin>>T;
    for (int _=0; _<T; _++)
        solve();

}