n,k = map(int,input().split())
ans = 0
dp = [0]
for i in range(n):
    a,m = map(int,input().split())
    dp.append(ans-a)
    B = list(map(int,input().split()))
    for b in B:
        dp[-1] = max(dp[-1],dp[b])
    ans = max(ans,dp[-1]+a)
print(ans)