import java.util.Scanner;

public class GridMaxSum {

public int solution(int num, int[][] arr){

int answer = Integer.MIN_VALUE;

int sum1, sum2;

for(int i=0;i<num;i++){

sum1=sum2=0;

for(int j=0;j<num;j++){

sum1 += arr[i][j];

sum2 += arr[j][i];

}

answer = Math.max(answer, sum1);

answer = Math.max(answer, sum2);

}

sum1=sum2=0;

for (int i=0;i<num;i++){

sum1 += arr[i][i];

sum2 += arr[num-i-1][num-i-1];

}

answer = Math.max(answer, sum1);

answer = Math.max(answer, sum2);

return answer;

}

public static void main(String[] args) {

GridMaxSum t = new GridMaxSum();

Scanner scanner = new Scanner(System.in);

int n = scanner.nextInt();

int[][] arr = new int[n][n];

for (int i=0;i<n;i++){

for(int j=0;j<n;j++){

arr[i][j] = scanner.nextInt();

}

}

System.out.println(t.solution(n, arr));

}

}