#include <fstream>

#define LONG_MIN -99999999999LL

using namespace std;

int n, m;
int a[16][16];
int s1[16], s2[16];

int main()
{
	ifstream f("flip.in");
	ofstream f2("flip.out");

	f>>n>>m;


	for(int i = 0; i < n; ++i)
		for(int j = 0; j < m; ++j)
		{
			f>>a[i][j];
			s1[i] += a[i][j];
			s2[i] -= a[i][j];
		}


	int best = LONG_MIN;
	for(int p = 0; p < (1<<n); ++p)
	{
		 int crt = 0;
		 
		 for(int i = 0; i < m; ++i)
		 {
			int c1 = 0, c2 = 0;
			for(int j = 0; j < n; ++j)
			{
				int coef = 1;
				if( (1<<j) & p ) coef = -1;
				c1 += a[j][i] * coef;
				c2 -= a[j][i] * coef;
			}
			crt += max(c1,c2);
		 }

		 if(crt > best) best = crt;
	}
	f2<<best;
}