import java.io.*;


public class Flip {

	private static Integer n, m;
	private static Integer[][] map;
	
	public static void main(String [] args) throws FileNotFoundException, UnsupportedEncodingException {
		read();
		for (int i=0; i<n; i++)
			if (checkRow(i) > 0)
				switchRow(i);
		for (int i=0; i<m; i++)
			if (checkColumn(i) > 0)
				switchColumn(i);
		PrintWriter writer = new PrintWriter("flip.out", "UTF-8");
		writer.println(getSum());
		writer.close();
    }
	
	public static void read() {
		String path = System.getProperty("user.dir");
        String fileName = path + "\\src\\text.txt";

        try {
            FileReader fileReader = new FileReader(fileName);
            BufferedReader bufferedReader = new BufferedReader(fileReader);
            String line = null;
            
            line = bufferedReader.readLine();
            String[] p = line.split(" ");
            n = Integer.parseInt(p[0]);
            m = Integer.parseInt(p[1]);
            map = new Integer[n][m];
            
            for (int i=0; i<n; i++) {
            	line = bufferedReader.readLine();
                p = line.split(" ");
                for (int j=0; j<m; j++)
                	map[i][j] = Integer.parseInt(p[j]);
            }
            bufferedReader.close();         
        }
        catch(FileNotFoundException ex) {
            System.out.println(
                "Unable to open file '" +
                fileName + "'");                
        }
        catch(IOException ex) {
            System.out.println(
                "Error reading file '"
                + fileName + "'");            
        }
	}
	
	public static void switchRow(int r) {
		for (int i=0; i<m; i++)
			map[r][i] = -map[r][i];
	}
	public static void switchColumn(int c) {
		for (int i=0; i<n; i++)
			map[i][c] = -map[i][c];
	}
	
	public static int getSum() {
		int result = 0;
		for (int i=0; i<n; i++)
			for (int j=0; j<m; j++)
				result += map[i][j];
		return result;
	}
	
	public static int getSumRow(int r) {
		int result = 0;
		for (int i=0; i<m; i++)
			result += map[r][i];
		return result;
	}
	public static int getSumColumn(int c) {
		int result = 0;
		for (int i=0; i<n; i++)
			result += map[i][c];
		return result;
	}
	
	public static int checkRow(int r) {
		return -2 * getSumRow(r);
	}
	public static int checkColumn(int c) {
		return -2 * getSumColumn(c);
	}
	
}