#ifdef LOCAL
//#define _GLIBCXX_DEBUG
#endif
//#pragma GCC target("avx512f,avx512dq,avx512cd,avx512bw,avx512vl")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> P;
typedef pair<int, int> Pi;
typedef vector<ll> Vec;
typedef vector<int> Vi;
typedef vector<string> Vs;
typedef vector<char> Vc;
typedef vector<P> VP;
typedef vector<vector<ll>> VV;
typedef vector<vector<int>> VVi;
typedef vector<vector<char>> VVc;
typedef vector<vector<vector<ll>>> VVV;
typedef vector<vector<vector<vector<ll>>>> VVVV;

#define endl '\n'
#define REP(i, a, b) for(ll i=(a); i<(b); i++)
#define PER(i, a, b) for(ll i=(a); i>=(b); i--)
#define rep(i, n) REP(i, 0, n)
#define per(i, n) PER(i, n, 0)
const ll INF = 1e18+18;
const ll MOD = 1000000007;
#define Yes(n) cout << ((n) ? "Yes" : "No") << endl;
#define YES(n) cout << ((n) ? "YES" : "NO") << endl;
#define ALL(v) v.begin(), v.end()
#define rALL(v) v.rbegin(), v.rend()
#define pb(x) push_back(x)
#define mp(a, b) make_pair(a,b)
#define Each(a, b) for(auto &a :b)
#define rEach(i, mp) for (auto i = mp.rbegin(); i != mp.rend(); ++i)
#ifdef LOCAL
#define dbg(x_) cerr << #x_ << ":" << x_ << endl;
#define dbgmap(mp) cerr << #mp << ":"<<endl; for (auto i = mp.begin(); i != mp.end(); ++i) { cerr << i->first <<":"<<i->second << endl;}
#define dbgset(st) cerr << #st << ":"<<endl; for (auto i = st.begin(); i != st.end(); ++i) { cerr << *i <<" ";}cerr<<endl;
#define dbgarr(n, m, arr) rep(i,n){rep(j,m){cerr<<arr[i][j]<<" ";}cerr<<endl;}
#define dbgdp(n, arr) rep(i,n){cerr<<arr[i]<<" ";}cerr<<endl;
#else
#define dbg(...)
#define dbgmap(...)
#define dbgset(...)
#define dbgarr(...)
#define dbgdp(...)
#endif
#define out(a) cout<<a<<endl
#define out2(a, b) cout<<a<<" "<<b<<endl
#define vout(v) rep(i,v.size()){cout<<v[i]<<" ";}cout<<endl
#define Uniq(v) v.erase(unique(v.begin(), v.end()), v.end())
#define fi first
#define se second

template<class T>
bool chmax(T &a, const T &b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}

template<class T>
bool chmin(T &a, const T &b) {
    if(b < a) {
        a = b;
        return true;
    }
    return false;
}

template<typename T1, typename T2>
ostream &operator<<(ostream &s, const pair<T1, T2> &p) { return s<<"("<<p.first<<", "<<p.second<<")"; }

template<typename T>
istream &operator>>(istream &i, vector<T> &v) {
    rep(j, v.size())i>>v[j];
    return i;
}

// vector
template<typename T>
ostream &operator<<(ostream &s, const vector<T> &v) {
    int len = v.size();
    for(int i = 0; i < len; ++i) {
        s<<v[i];
        if(i < len-1) s<<"	";
    }
    return s;
}

// 2 dimentional vector
template<typename T>
ostream &operator<<(ostream &s, const vector<vector<T> > &vv) {
    s<<endl;
    int len = vv.size();
    for(int i = 0; i < len; ++i) {
        s<<vv[i]<<endl;
    }
    return s;
}


void dijkstra(vector<VP> &g, ll start, Vec &dist) {
    priority_queue<P, vector<P>, function<bool(P, P)>> q([](P a, P b)->ll {
        return a.second > b.second;
    });
    dist[start] = 0;
    q.push(mp(start, 0));
    while (!q.empty()) {
        P now = q.top();
        q.pop();
        if(dist[now.fi] < now.se) continue;
        Each(nxt, g[now.fi]) {
            if(chmin(dist[nxt.fi], now.se+nxt.se)) {
                q.push(mp(nxt.fi, dist[nxt.fi]));
            }
        }
    }
}


int solve() {
    ll n;
    cin>>n;
    ll k;
    cin>>k;
    Vec A(n);
    VV g(n);

    rep(i, n) {
        cin>>A[i];
        ll m;
        cin>>m;
        rep(j, m) {
            ll b;
            cin>>b;
            b--;
            g[i].pb(b);
        }
    }
    dbg(g);
    dbg(A);
    Vec dp(n+1,-INF);
    dp[0] = 0;
    rep(i, n) {
        chmax(dp[i+1], dp[i]);
        Each(j, g[i]) {
            //交換
            chmax(dp[i+1], dp[j+1] + A[i]-A[j]);
        }
    }
    ll ans = 0;
    rep(i,n){
        chmax(ans, dp[i+1]);
    }
    dbg(dp);
    out(ans);
    return 0;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout<<std::setprecision(10);
//    ll T;
//    cin>>T;
//    while(T--)
    solve();
}