"""

1676 & 8

flowかねぇ


"""

import sys
from sys import stdin
import heapq

N,K = map(int,stdin.readline().split())

A = []
B = []

for i in range(N):

    a,m = map(int,stdin.readline().split())
    b = list(map(int,stdin.readline().split()))

    for j in range(m):
        b[j] -= 1

    A.append(a)
    B.append(b)

if K == 1: #1676

    dp = [0] * N

    for i in range(N):

        if i != 0:
            dp[i] = max(dp[i] , dp[i-1])
        
        for v in B[i]:
            dp[i] = max(dp[i] , dp[v] + A[i] - A[v])

    print (dp[-1])