#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(n); i++)





int main(){
  int N,K; cin >> N >> K;
  vector<i64> A(N);
  vector<vector<int>> E(N);
  rep(i,N){
    int c; cin >> A[i] >> c;
    E[i].resize(c);
    rep(j,c){ cin >> E[i][j]; E[i][j]--; }
  }

  vector<i64> dp(N+1,0);
  rep(i,N){
    for(int e : E[i]){
      dp[i] = max(dp[i], dp[e] - A[e] + A[i]);
    }
    dp[i+1] = max(dp[i+1], dp[i]);
  }

  cout << dp.back() << endl;
  return 0;
}




struct ios_do_not_sync {
    ios_do_not_sync() {
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;