import java.util.*; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n= sc.nextInt(); int k=sc.nextInt(); int[][] teki= new int[1001][1001]; int[][] dame = new int[1555][1555]; for(int i=0;i0){ ans+=Math.max(0,teki[i][j]-dame[i][j]); } } } System.out.println(ans); } }