Count sources

A directed graph is given in the form of an adjacency list. A vertex of the graph is called a source if no edges enter it.

Determine the number of sources in the given graph.

Input

The first line contains the number of vertices of the graph n~(1 \le n \le 100).

The adjacency list of the graph follows: the $i$-th line contains information about vertex $i$. First, the number of edges outgoing from this vertex is given, followed by the indices of adjacent vertices in increasing order.

Output

Print the number of source vertices in the graph.

Example

In the given graph, there is one source — vertex number $4$.