#include <fstream>

using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
int n, m, a[20][20], x[20], maxim;
bool c[20];
void Calculare()
{int sum = 0;
for(int j=1; j <=m; j++)
{  int sum2 = 0;
for(int i=1; i<=n; i++)
	if(c[i]) sum2 += -a[i][j];
	else sum2 += a[i][j];
	if(sum2 < -sum2)
		sum2 = -sum2;
	sum += sum2;
	if(maxim < sum) maxim = sum;
}}
void Back(int k)
{    if(k == n+1) Calculare();
else        for(int j=0; j<=1; j++)
{            c[k] = j;
Back(k+1);
}}
int main()
{    f>>n>>m;
for(int i=1; i<=n; i++)
	for(int j=1; j<=m; j++)
		f>>a[i][j];
Back(1);
g<<maxim;
return 0;
}