import java.util.*;

public class Main {
    static int[][] matrix;
    static int n;
    static HashMap<Integer, Integer> map = new HashMap<>();
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        matrix = new int[n][n];
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                matrix[i][j] = sc.nextInt();
            }
        }
        System.out.println(getCount(0));
    }
    
    static int getCount(int key) {
        if (key == (int)(Math.pow(2, n)) - 1) {
            return 0;
        }
        if (map.containsKey(key)) {
            return map.get(key);
        }
        int max = 0;
        for (int i = 0; i < n; i++) {
            if (((int)(Math.pow(2, i)) & key) != 0) {
                continue;
            }
            for (int j = i + 1; j < n; j++) {
                if (((int)(Math.pow(2, j)) & key) != 0) {
                    continue;
                }
                max = Math.max(max, matrix[i][j] + getCount(key + (int)(Math.pow(2, i)) + (int)(Math.pow(2, j))));
            }
        }
        map.put(key, max);
        return max;
    }
}