package com.company;
import java.io.*;
import java.util.*;
public class Main {
static int[][] arr, check, startPoint;
static boolean[][] visited;
static int[][] d = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
static int N, answer;
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = null;
answer = Integer.MAX_VALUE;
N = Integer.parseInt(br.readLine());
arr = new int[N][N];
check = new int[N][N];
visited = new boolean[N][N];
startPoint = new int[][]{{0, 0}, {0, N - 1}, {N - 1, 0}, {N - 1, N - 1}, {0, 0}};
for (int i = 0; i < N; i++) {
st = new StringTokenizer(br.readLine());
for (int j = 0; j < N; j++) {
arr[i][j] = Integer.parseInt(st.nextToken());
}
}
for (int i = 0; i < N; i++) {
for (int j = 0; j < N; j++) {
findD(i, j);
}
}
System.out.println(answer);
}
static void findD(int x, int y) {
for (int d1 = 1; d1 < N; d1++) {
for (int d2 = 1; d2 < N; d2++) {
if (x + d1 + d2 < N && 0 <= y - d1 && y + d2 < N) {
check = new int[N][N];
visited = new boolean[N][N];
startPoint[4][0] = x+1;
startPoint[4][1] = y;
divide(x, y, d1, d2);
int max = 0;
int min = Integer.MAX_VALUE;
for (int i = 0; i < 5; i++) {
int a = population(startPoint[i][0], startPoint[i][1], i + 1);
max = Math.max(a, max);
min = Math.min(a, min);
}
answer = Math.min(max - min, answer);
}
}
}
}
static void divide(int x, int y, int d1, int d2) {
for (int i = 0; i <= d1; i++) {
check[x + i][y - i] = 5;
check[x + d2 + i][y + d2 - i] = 5;
}
for (int i = 0; i <= d2; i++) {
check[x + i][y + i] = 5;
check[x + d1 + i][y - d1 + i] = 5;
}
int temp = 1;
while (x - temp >= 0) {
check[x - temp++][y] = 1;
}
temp = 1;
while (y + d2 + temp < N) {
check[x + d2][y + d2 + temp++] = 2;
}
temp = 1;
while (y - d1 - temp >= 0) {
check[x + d1][y - d1 - temp++] = 3;
}
temp = 1;
while (x + d2 + d1 + temp < N) {
check[x + d2 + d1 + temp++][y + d2 - d1] = 4;
}
}
static int population(int x, int y, int num) {
int count = 0;
Queue<int[]> q = new LinkedList<>();
q.add(new int[]{x, y});
visited[x][y] = true;
while (!q.isEmpty()) {
int[] node = q.poll();
count += arr[node[0]][node[1]];
if (num != 5 && check[node[0]][node[1]] == num) {
continue;
}
for (int[] i : d) {
int nextX = node[0] + i[0];
int nextY = node[1] + i[1];
if (nextX >= 0 && nextY >= 0 && nextX < N && nextY < N
&& !visited[nextX][nextY] && (check[nextX][nextY] == num || check[nextX][nextY] == 0)) {
q.add(new int[]{nextX, nextY});
visited[nextX][nextY] = true;
}
}
}
return count;
}
}