import java.util.*;
public class piramide{

    public static void main(String[] args){
        Scanner s = new Scanner(System.in);
        int N = s.nextInt();
        int[][] pilha = new int[N][N];
        for(int i = 0; i < N; i++){
            for(int j = 0; j < N; j++){
                pilha[i][j] = s.nextInt();
            }
        }
        for(int i = 0; i < N; i++){
            Arrays.sort(pilha[i]);
        }
        int sum = 0;

        for(int i = N-1; i >= 0 ; --i){
            for(int j = 0; j <= i; j++){
                sum += pilha[i][j];
            }
        }

        System.out.println(sum);

    }

}