A9630 | Gargari and Permutations

Gargari got bored to play with the bishops and now, after solving the problem about them, he is trying to do math homework. In a math book he have found $k$ permutations. Each of them consists of numbers $1,2,...,n$ in some order. Now he should find the length of the longest common subsequence of these permutations. Can you help Gargari?

You can read about longest common subsequence there: https://en.wikipedia.org/wiki/Longest\_common\_subsequence\_problem

The first line contains two integers $n$ and $k$ $(1<=n<=1000; 2<=k<=5)$ . Each of the next $k$ lines contains integers $1,2,...,n$ in some order — description of the current permutation.

Print the length of the longest common subsequence.