#include <stdio.h>
#include <algorithm>
#include <vector>
#include <queue>

using namespace std;

int n , m , tot;
int a[120][120];
int top[12000] , bottom[12000];
int tp[4] , ttp;
vector < int > g[12000] , rg[12000];
int dis[4][12000] , rdis[12000];
int ans;
void getdis ( int i ) {
	int j , k;
	queue < int > q;
	for ( j = 1 ; j <= tot + 1 ; j++ ) {
		dis[i][j] = -1;
	}
	dis[i][tp[i]] = 0;
	q.push ( tp[i] );
	while ( q.size () ) {
		k = q.front (); q.pop ();
		for ( auto l : g[k] ) {
			if ( dis[i][l] == -1 ) {
				dis[i][l] = dis[i][k] + 1;
				q.push ( l );
			}
		}
	}
}
void getrdis () {
	int j , k;
	queue < int > q;
	for ( j = 1 ; j <= tot + 1 ; j++ ) {
		rdis[j] = -1;
	}
	rdis[tot+1] = 0;
	q.push ( tot + 1 );
	while ( q.size () ) {
		k = q.front (); q.pop ();
		for ( auto l : rg[k] ) {
			if ( rdis[l] == -1 ) {
				rdis[l] = rdis[k] + 1;
				q.push ( l );
			}
		}
	}
}
void work () {
	int i , j;
	scanf ( "%d%d" , &n , &m );
	tot = 0;
	for ( i = 1 ; i <= n ; i++ ) {
		for ( j = 1 ; j <= m ; j++ ) {
			scanf ( "%d" , &a[i][j] );
			if ( i == 1 ) {
				top[a[i][j]] = 1;
			}
			if ( i == n ) {
				bottom[a[i][j]] = 1;
			}
			tot = max ( tot , a[i][j] );
		}
	}
	for ( i = 1 ; i <= tot ; i++ ) {
		if ( top[i] == 1 ) tp[++ttp] = i;
	}
	for ( i = 1 ; i < n ; i++ ) {
		for ( j = 1 ; j <= m ; j++ ) {
			if ( a[i][j] != a[i+1][j] ) {
				g[a[i][j]].push_back( a[i+1][j] );
				rg[a[i+1][j]].push_back( a[i][j] );
			}
		}
	}
	for ( i = 1 ; i <= tot ; i++ ) {
		if ( bottom[i] == 1 ) {
			//printf ( "##%d\n" , i );
			g[i].push_back(tot+1);
			rg[tot+1].push_back(i);
		}
	}
	for ( i = 1 ; i <= ttp ; i++ ) {
		getdis ( i );
	}
	if ( ttp == 1 ) {
		printf ( "%d\n" , dis[1][tot+1] );
		return ;
	}
	getrdis ();
	/*for ( i = 1 ; i <= tot + 1 ; i++ ) {
		printf ( "%d %d %d\n" , dis[1][i] , dis[2][i] , rdis[i] );
	}*/
	ans = dis[1][tot+1] + dis[2][tot+1];
	for ( i = 1 ; i <= tot ; i++ ) {
		if ( dis[1][i] == -1 ) continue;
		if ( dis[2][i] == -1 ) continue;
		if ( rdis[i] == -1 ) continue;
		ans = min ( ans , dis[1][i] + dis[2][i] + rdis[i] );
	}
	printf ( "%d\n" , ans );
}
int main () {
	work ();
	return 0;
}