import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;


public class Main {

	public static void main(String [] args){
		try {
			Scanner s = new Scanner(new FileInputStream("flip.in"));
			PrintWriter p = new PrintWriter("flip.out");
			int m,n,i,j,aux;
			int matrice[][]=new int[20][20];
			
			m=s.nextInt();
			n=s.nextInt();
			
			for(i=1;i<=m;i++){
				for(j=1;j<=n;j++){
					aux=s.nextInt();
					matrice[i][j]=aux;
					//p.print(matrice[i][j]+" ");
				}
				//p.print("\n");
			}
			
			for(i=1;i<=m;i++){
				aux=0;
				for(j=1;j<=n;j++){
					aux=aux+matrice[i][j];
				}
				matrice[i][n+1]=aux;				
			}
			
			for(j=1;j<=n;j++){
				aux=0;
				for(i=1;i<=m;i++){
					aux=aux+matrice[i][j];
				}
				matrice[m+1][j]=aux;
			}
			
			for(i=1;i<=m;i++){
				if(matrice[i][n+1]<0){
					for(j=1;j<=n;j++){
						matrice[i][j]=matrice[i][j]*(-1);
					}
				}
								
			}
			for(j=1;j<=n;j++){
				if(matrice[m+1][j]<0){
					for(i=1;i<=m;i++){
						matrice[i][j]=matrice[i][j]*(-1);
					}
				}
			}
			
			
/*			for(i=0;i<20;i++){
				for(j=0;j<20;j++){
					p.print(matrice[i][j]+" ");
				}
				p.print("\n");
			}
*/			
			aux=0;
			for(i=1;i<=m;i++){
				for(j=1;j<=n;j++){
					aux+=matrice[i][j];
				}
			}
			
			p.print(aux);
			
			s.close();
			p.close();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
}