#include<bits/stdc++.h>
using namespace std;
int go[4][2]={{1,0},{-1,0},{0,-1},{0,1}};
int mapp[501][501],n,vis[501][501],minn=INT_MAX,minnn=INT_MAX,dx,dy;
void dfs(int x,int y,int step,int sum,int num){
	vis[x][y]=1;
	num=mapp[x][y];
	if(step==n*n/2){
		if(sum<minn){
			minn=sum;
		}
		return ;
	}
	if(sum>=minn){
		return ;
	}
	for(int i=0;i<4;i++){
		int xx=x+go[i][0];
		int yy=y+go[i][1];
		if(x>=1&&x<=n&&y>=1&&y<=n&&!vis[xx][yy]){
			vis[xx][yy]=1;
			dfs(xx,yy,step+1,sum+abs(mapp[xx][yy]-num),mapp[xx][yy]);
			vis[xx][yy]=0;
		}
	}
}
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			cin>>mapp[i][j];
			if(mapp[i][j]<minnn){
				minnn=mapp[i][j];
				dx=i;
				dy=j;
			}
		}
	}
	dfs(dx,dy,0,0,0);
	cout<<minn;
	return 0;
}