#include<fstream>
#include<string.h>
#include<ctype.h>
#include<iostream>
#include<algorithm>
#include<map>
#include<unordered_map>
#include<array>
#include<deque>
#include<math.h>
#include<unordered_set>
#include<queue>
#include<set>
#include<iomanip>
#include<bitset>
using namespace std;
string number;
int n, m, mat[17][17],i,j,k,ok,nr,el,max1,bitmax,val;
int calccol(int y, int nr)
{
	int rez=0;
	for (int i = 1; i <= n; i++)
		if (nr&1<<i)
			rez += -1 * mat[i][y];
		else
			rez += mat[i][y];
	if (rez >= 0)
		return rez;
	else
		return -1 * rez;
}
int main()
{
	//ifstream f("file.in");
	//ofstream g("file.out");
	ifstream f("flip.in");
	ofstream g("flip.out");
	f >> n >> m;
	for (i = 1; i <= n; i++)
		for (j = 1; j <= m; j++)
			f >> mat[i][j];
	bitmax = pow(2, n);
	for (i = 0; i <= bitmax - 1; i++)
	{
		val = 0;
		for (j = 1; j <= m; j++)
			val += calccol(j, i);
		if (val > max1)
			max1 = val;
	}
	g << max1;
	return 0;
}