//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#include <iostream>
#include <algorithm>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using mint = modint1000000007;
using ll = long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using vi = vector<int>;  using vvi = vector<vi>;
using vl = vector<ll>;   using vvl = vector<vl>;
using vb = vector<bool>; using vvb = vector<vb>;
using vm = vector<mint>; using vvm = vector<vm>;
using vpi = vector<pii>; using vvpi = vector<vpi>;
using vpl = vector<pll>; using vvpl = vector<vpl>;
const int inf = 1 << 30;
const ll INF = 1LL << 60;
#define rep(i,m,n) for (int i = m; i < (int)(n); i++)
#define rrep(i,m,n) for (int i = m; i > (int)(n); i--)

int main(){
    int n,k; cin >> n >> k;
    vi A(n);
    vvpi G(n);
    rep(i,0,n){
        int a,m; cin >> a >> m;
        A[i] = a;
        rep(j,0,m){
            int b; cin >> b; --b;
            G[b].push_back({i,a-A[b]});
        }
    }
    vl dp(n+1);
    rep(i,0,n){
        dp[i+1] = max(dp[i],dp[i+1]);
        for (auto p:G[i]){
            int j = p.first, b = p.second;
            dp[j] = max(dp[i]+b,dp[j]);
        }
    }
    cout << dp[n] << endl;
}