#include <iostream>
#include <fstream>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");


int main()
{
	int a[20][20],sumN,sum,bigS=0;
	unsigned int m, n, i, j;
	f >> n; f >> m;
	if (n < 1 || n>16 || m < 1 || n>16)
		g << 0;
	for (i = 1; i <= n; i++)
		for (j = 1; j <= m; j++)
		{
			f >> a[i][j];
		}
	for (i = 1; i <= n; i++)
	{
		sum = 0;
		sumN = 0;
		for (j = 1; j <= m; j++)
		{
			sum = sum + a[i][ j ];
			sumN = sumN - a[i][j];
		}
		if (sumN > sum)
		{
			for (j = 1; j <= n; j++)
				a[i][j] = -a[i][j];
		}
	}
	for (i = 1; i <= m; i++)
	{
		sum = 0;
		sumN = 0;
		for (j = 1; j <= n; j++)
		{
			sum = sum + a[j][i];
			sumN = sumN - a[j][i];
		}
		if (sumN > sum)
		{
			for (j = 1; j <= n; j++)
				a[j][i] = -a[j][i];
			sum = sumN;
		}
		bigS = bigS + sum;

	}
	g << bigS;
	return 0;
}