from sys import stdin
n, m, *indata = map(int, stdin.read().split())
offset = 0
pricetable = [0 for i in range(n+1)]
dp = [0 for i in range(n+1)]
for i in range(n):
    a, m = indata[offset],indata[offset + 1]
    offset += 2
    dp[i+1] = dp[i]
    for j in range(m):
        b = indata[offset + j]
        dp[i+1] = max(dp[i+1],dp[b]-pricetable[b]+a)
    pricetable[i+1] = a
    offset += m
print("{}".format(dp[n]))