#![allow(unused_imports)]
#![allow(non_snake_case, unused)]

// ---------- begin input macro ----------
// https://atcoder.jp/contests/hokudai-hitachi2019-1/submissions/10518254 より
pub fn readln() -> String {
    let mut line = String::new();
    ::std::io::stdin().read_line(&mut line).unwrap_or_else(|e| panic!("{}", e));
    line
}

macro_rules! read {
    ($($t:tt),*; $n:expr) => {{
        let stdin = ::std::io::stdin();
        let ret = ::std::io::BufRead::lines(stdin.lock()).take($n).map(|line| {
            let line = line.unwrap();
            let mut it = line.split_whitespace();
            _read!(it; $($t),*)
        }).collect::<Vec<_>>();
        ret
    }};
    ($($t:tt),*) => {{
        let line = readln();
        let mut it = line.split_whitespace();
        _read!(it; $($t),*)
    }};
}

macro_rules! _read {
    ($it:ident; [char]) => {
        _read!($it; String).chars().collect::<Vec<_>>()
    };
    ($it:ident; [u8]) => {
        Vec::from(_read!($it; String).into_bytes())
    };
    ($it:ident; usize1) => {
        $it.next().unwrap_or_else(|| panic!("input mismatch")).parse::<usize>().unwrap_or_else(|e| panic!("{}", e)) - 1
    };
    ($it:ident; [usize1]) => {
        $it.map(|s| s.parse::<usize>().unwrap_or_else(|e| panic!("{}", e)) - 1).collect::<Vec<_>>()
    };
    ($it:ident; [$t:ty]) => {
        $it.map(|s| s.parse::<$t>().unwrap_or_else(|e| panic!("{}", e))).collect::<Vec<_>>()
    };
    ($it:ident; $t:ty) => {
        $it.next().unwrap_or_else(|| panic!("input mismatch")).parse::<$t>().unwrap_or_else(|e| panic!("{}", e))
    };
    ($it:ident; $($t:tt),+) => {
        ($(_read!($it; $t)),*)
    };
}
// ---------- end input macro ----------


use std::cmp::*;
use std::collections::*;
use std::ops::*;
use std::marker::*;
 
const INF: i64 = std::i64::MAX/100;
const MOD: i64 = 1_000_000_007;
// const MOD: i64 = 998_244_353;

fn main() {
    let (n,m) = read!(usize,usize);
    let mut a = vec![];
    let mut edge = vec![vec![];n];
    for i in 0..n {
        let (v,m) = read!(i64,usize);
        let b = read!([usize]);
        a.push(v);
        for &b in &b {
            edge[b-1].push(i);
        }
    }
    let mut dp = vec![vec![0;2];n];
    for i in 0..n {
        dp[i][1] = -a[i];
    }
    for v in 0..n {
        if v>0 {
            dp[v][0] = dp[v][0].max(dp[v-1][0]);
        }
        dp[v][0] = dp[v][0].max(dp[v][1]+a[v]);
        dp[v][1] = dp[v][1].max(dp[v][0]-a[v]);
        for &e in &edge[v] {
            dp[e][0] = dp[e][0].max(dp[v][0]);
            dp[e][1] = dp[e][1].max(dp[v][1]);
        }
    }
    let mut ans = 0;
    for i in 0..n {
        ans = ans.max(dp[i][0]);
        ans = ans.max(dp[i][1]+a[i]);
    }
    println!("{}",ans);
}