import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = 10**20
md = 998244353
# md = 10**9+7

n, k = LI()
dp = [0]+[-inf]*n
aa = [0]*n

for i in range(n):
    a, m = LI()
    bb = LI1()
    aa[i] = a
    dp[i+1] = dp[i]
    for b in bb:
        cur = dp[b+1]+a-aa[b]
        if cur>dp[i+1]:dp[i+1]=cur

print(dp[-1])