This problem contains several cases.
The first line of each case is two integers N and M (1 <= M <= N <= 500), indicate the number of STANMASH team's members and another team's members.
Then follow N lines. The first integer of ith line Ki indicates the number of enemies that ith team member can kill (0 <= Ki <= M). Then follow Ki integers, each integer is the ID of enemy that he can kill. (1 <= ID <= M)
For each case, you should output that the maximum number of enemies that they can kill.