package src;

import java.util.*;
class B{
	static Scanner s = new Scanner(System.in);
	public static void main(String[] args) {
		int size = s.nextInt();
		int[][] in = new int[size][size];
		Card[] cards = new Card[s.nextInt()];
		for (int i=0;i<cards.length;i++) {

			for(int j=0;j<size;j++)
				for(int k=0;k<size;k++)
					in[j][k] = Integer.parseInt(s.next());

			cards[i] = new Card(in,size*size*cards.length);
		}
		int v=0;
		for(int i=0;i<cards.length;i++) {
			for(int j=i+1;j<cards.length;j++) {
				v=Math.max(v, cards[i].match(cards[j]));
			}
		}
		System.out.println(size*2-1-v);
	}
}
class Card{
	ArrayList<BitSet> edge;
	Card(int[][] in,int max) {
		int size = in.length;
		edge = new ArrayList<>(in.length*2+2);
		BitSet
			h =new BitSet(max),
			v =new BitSet(max),
			t1=new BitSet(max),
			t2=new BitSet(max);

		for(int i=0;i<size;++i) {
			h.clear();
			v.clear();
			for(int j=0;j<size;++j) {
				h.set(in[i][j]);
				v.set(in[j][i]);
			}
			edge.add((BitSet)h.clone());
			edge.add((BitSet)v.clone());
			t1.set(in[i][i]);
			t2.set(in[i][size-i-1]);
		}
		edge.add(t1);
		edge.add(t2);
	}

	public int match(Card card) {
		int r=0,max=edge.get(0).cardinality();
		roop:
		for(int i=0;i<edge.size();i++) {
			BitSet b = card.edge.get(i);
			for(int j=0;j<edge.size();j++) {
				BitSet bb = ((BitSet) b.clone());
				bb.and(edge.get(j));
				r=Math.max(r, bb.cardinality());
				if(r==max)
					break roop;
			}
		}
		return r;
	}
}