#ifdef DEBUG
#define _GLIBCXX_DEBUG
#endif
//#pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;

#define X first
#define Y second

const ll mod = 1000000007;

void solve()
{
    ll n, C;
    cin >> n >> C;
    vector<ll> prv(C,mod*mod);
    vector<pair<ll,ll>> Q;
    for (ll i=0;i<n;i++)
    {
        ll x, k;
        cin >> x >> k;
        x *= 2;
        for (ll j=0;j<k;j++)
        {
            ll w;
            cin >> w;
            w--;
            Q.push_back({x,w});
        }
    }
    sort(Q.begin(),Q.end());
    vector<pair<ll,ll>> ord;
    ll S = 0;
    ll A = mod*mod;
    for (ll i=0;i<Q.size();i++)
    {
        ll p = Q[i].Y, x = Q[i].X;
        ord.push_back({x,2});
        if (prv[p]==mod*mod)
        {
            S += x;
            prv[p] = x;
            continue;
        }
        ord.push_back({(x+prv[p])/2,-2});
        prv[p] = x;
    }
    sort(ord.begin(),ord.end());
    ll D = -C;
    S = S-C*ord[0].X;
    A = S;
    for (ll i=0;i<ord.size();i++)
    {
        if (i>0)
        {
            ll del = ord[i].X-ord[i-1].X;
            S += del*D;
            A = min(A,S);
        }
        D += ord[i].Y;
    }
    cout << A/2 << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
//#ifdef DEBUG
//    freopen("input.txt", "r", stdin);
//#endif
    ll T = 1;
    cin >> T;
    while (T--) solve();
    return 0;
}