static void createEdge(node a, node b)
{
edges fwd = new edges(a.key, b.key, 0, 1);
edges bckwd = new edges(b.key, a.key, 1, 1);
a.neighbours.Add(b.key, fwd);
b.neighbours.Add(a.key, bckwd);
}
static void Main(string[] args)
{
string[] input = Console.ReadLine().Split();
int len = int.Parse(input[0]);
node[] rcities = new node[len * 2 + 2];
for (int i = 1; i <= len; i++)
{
rcities[i] = new node();
rcities[i].key = i;
rcities[i].keys = new int[int.Parse(input[1])];
string[] key = Console.ReadLine().Split();
for (int j = 0; j < int.Parse(input[1]); j++)
{
rcities[i].keys[j] = int.Parse(key[j]);
}
rcities[i + len] = new node();
rcities[i + len].key = i + len;
rcities[i + len].keys = new int[int.Parse(input[1])];
for (int j = 0; j < int.Parse(input[1]); j++)
{
rcities[i + len].keys[j] = int.Parse(key[j]);
}
}
createGraph(rcities, int.Parse(input[0]), int.Parse(input[1]));
//add start edge
rcities[0] = new node();
rcities[len * 2 + 2 - 1] = new node();
rcities[len * 2 + 2 - 1].key = len * 2 + 2 - 1;
for (int i = 0; i < int.Parse(input[0]); i++)
{
edges fwd = new edges(0, i + 1, 1, 1);
edges backwd = new edges(i + 1, 0, 0, 1);
rcities[0].neighbours.Add(i + 1, fwd);
rcities[i + 1].neighbours.Add(0, backwd);
}
//add backward node edge
for (int i = int.Parse(input[0]) + 1; i < (2 * len + 2) - 1; i++)
{
edges fwd = new edges(i, (2 * len + 2) - 1, 1, 1);
edges backwd = new edges((2 * len + 2) - 1, i, 0, 1);
rcities[i].neighbours.Add((2 * len + 2) - 1, fwd);
rcities[(2 * len + 2) - 1].neighbours.Add(i, backwd);
}
int flow = calcFlow(rcities, len * 2 + 2);
Console.Write(int.Parse(input[0]) - flow);
Console.Read();
}