#include <iostream>
#include <fstream>
using namespace std;

ifstream fin("flip.in");
ofstream fout("flip.out");
int N, M, maxim, linesum, sum;

int matrice[20][20];
int maxsum()
{
	sum = 0;
	for (int i = 1; i <= N; i++)
	{
		linesum = 0;
		for (int j = 1; j <= M; j++)
		{
			linesum += matrice[i][j];
		}
		if (linesum < 0)
		{
			linesum = linesum * -1;
		}
		sum = sum + linesum;
	}
	return sum;
}
void BKT(int col)
{
	if (col <= M)
	{
		BKT(col + 1);
		for (int i = 1; i <= N; i++)
			matrice[i][col] *= -1;
		BKT(col + 1);
	}
	else
		maxim = max(maxim, maxsum());
}

int main()
{
	fin >> N >> M;

	for (int i = 0; i < N; i++)
	{
		for (int j = 0; j < M; j++)
		{
			fin >> matrice[i][j];
		}
	}

	for (int i = 1; i <= N; i++)
		for (int j = 1; j <= M; j++)
			fin >> matrice[i][j];

	BKT(1);
	fout << maxim;
	return 0;
}