Defragment

You are developing the file system for a new operating system. All disk space is divided into $N$ equally sized clusters, numbered from $1$ to $N$. Each file occupies one or more clusters located at arbitrary positions on the disk. Every cluster not occupied by a file is considered free.

A file can be read fastest when all of its clusters lie in consecutive clusters in their natural order. Because the disk rotates at a constant speed, clusters near the beginning are read faster than clusters near the end, so the files are numbered from $1$ to $K$ in order of decreasing access frequency. In the optimal layout, file $1$ occupies clusters $1, 2, \dots, S_1$, file $2$ occupies clusters $S_1+1, \dots, S_1+S_2$, and so on, where $S_i$ is the number of clusters that file $i$ occupies.

To reach the optimal layout you perform cluster-moving operations. One cluster-moving operation reads the contents of one occupied cluster and writes them to a free cluster; afterwards the source cluster becomes free and the destination cluster becomes occupied.

Compute the minimum number of cluster-moving operations required to place all files in the optimal layout.

The first line contains two integers $N$ and $K$ separated by a space ($1 \le K < N \le 10000$). Each of the next $K$ lines describes one file. The description of the $i$-th file starts with the integer $S_i$, the number of clusters in file $i$ ($1 \le S_i < N$), followed by $S_i$ integers giving the cluster numbers occupied by that file in natural order.

All cluster numbers in the input are distinct, and there is always at least one free cluster.

Print a single integer: the minimum number of cluster-moving operations needed to place all files in the optimal layout. If the files are already in the optimal layout, print $0$.