#include <bits/stdc++.h>
using namespace std;
int n, k, a[1005][1005], d[1005][1005], ans, D[10005];
pair<int, int> b[100005];
int ch(int x, int y) {
  for (int i = 1; i <= k; i++) {
    if (d[i][y] > d[i][x]) return 0;
  }
  return 1;
}
int main() {
  cin >> n >> k;
  for (int i = 1; i <= k; i++) {
    for (int j = 1; j <= n; j++) cin >> a[i][j];
    for (int j = 1; j <= n; j++) d[i][a[i][j]] = j;
    for (int j = 1; j <= n; j++) b[a[i][j]].first = max(b[a[i][j]].first, j);
  }
  for (int j = 1; j <= n; j++) b[j].second = j;
  sort(b + 1, b + n + 1);
  for (int i = 1; i <= n; i++) {
    int ma = 0;
    int I = b[i].second;
    for (int j = 1; j < i; j++) {
      int J = b[j].second;
      if (ch(I, J) && D[j] > ma) ma = D[j];
    }
    D[i] = ma + 1;
    ans = max(ans, D[i]);
  }
  cout << ans << endl;
  cin >> n;
}
