import sys
input = sys.stdin.readline

N,K=map(int,input().split())

V=[0]*N
C=[[] for i in range(N)]

for i in range(N):
    A,M=map(int,input().split())
    V[i]=A
    C[i]=list(map(int,input().split()))


DP=[0]*N


for i in range(N):
    v=V[i]

    MIN=1<<50

    DP[i]=max(DP[i],DP[i-1])

    for c in C[i]:
        c-=1
        DP[i]=max(DP[i],DP[c]+(v-V[c]))

print(max(DP))