import java.util.Scanner; import static java.lang.System.*; public class Main { public static void main(String[] args) { Scanner scan = new Scanner(in); int n = scan.nextInt(); int ax = 0; int ay = 0; int bx = n - 1; int by = 0; int a = 0; int b = 0; for (int y = 0; y < n; ++y) { for (int x = 0; x < n; ++x) { int c = scan.nextInt(); if (ax == x && ay == y) { a += c; ++ax; ++ay; } if (bx == x && by == y) { b += c; --bx; ++by; } } } out.println(Math.abs(a - b)); } }