#include <fstream>
#define IN "flip.in"
#define OUT "flip.out"
using namespace std;

int main()
{
	int M, N;
	int tabla[M][N];
	int sumeX[2][16], sumeY[2][16];
	ifstream fin ( IN );
	fin >> M >> N;
	for ( int i = 0; i < M; ++i )
	{
		for ( int j = 0; j < N; ++j )
		{
			fin >> tabla[i][j];
			if ( tabla[i][j] > 0 ) 
			{
				sumeX[0][i] += tabla[i][j];
				sumeY[0][j] += tabla[i][j];
			}
			else if ( tabla[i][j] < 0 ) 
			{
				sumeX[1][i] += ( tabla[i][j] * -1 );
				sumeY[1][j] += ( tabla[i][j] * -1 );
			}
		}
	}
	fin.close();

	int total = 0;
	for ( int i = 0; i < M; ++i )
	{
		if ( sumeX[0][i] > sumeX[1][i] ) total += sumeX[0][i];
		else total += sumeX[1][i];
	}
	for ( int j = 0; j < N; ++j )
	{
		if ( sumeY[0][i] > sumeY[1][j] ) total += sumeY[0][j];
		else total += sumeY[1][j];
	}
	
		
	ofstream fout ( OUT );
	fout << total << '\n';
	fout.close();
	
	return 0;
}