import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)

N, K = map(int, input().split())
dp = [-10 ** 9] * (N + 1)
dp[0] = 0
for i in range(1, N+1):
    A, M = map(int, input().split())
    B = list(map(int, input().split()))
    dp[i] = dp[0] - A

    res = dp[0]
    for b in B:
        res = max(res, A + dp[b])
    dp[0] = res

print(dp[0])