import java.util.*;

 public class Main {

     static int getit(int[][] a, int n) {

         if(n == 1) return a[0][0];

         if(n == 2) return a[0][0] * a[1][1] - a[0][1] * a[1][0];

         int[][] shuzu = new int[n-1][n-1];

         int ans = 0;

         for(int i = 0; i < n; ++i) {　　　　　　　　//每次将a[0][i]的行列去掉，赋值给一个新的数组

             for(int x = 0; x < n-1; ++x) {

                 for(int y = 0; y < i; ++y)

                     shuzu[x][y] = a[x+1][y];

                 for(int y = i; y < n-1; ++y)

                     shuzu[x][y] = a[x+1][y+1];

             }

             ans += a[0][i] * Math.pow(-1, i) * getit(shuzu, n-1);    //然后进行递归

         }

         return ans;

     }

     public static void main(String args[]) {

         Scanner sc = new Scanner(System.in);

         int n = sc.nextInt();

         int[][] shu = new int[n][n];

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

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

                 shu[i][j] = sc.nextInt();

         System.out.print(getit(shu, n));    

 }

 }