#include <iostream>
#include <fstream>
#include <math.h>

using namespace std;

int a[16][16];
int b[16][16];
int main()
{
	ifstream fin("flip.in");
	ofstream fout("flip.out");
	int n,m;
	fin>>n>>m;
	for (int i=0;i<n;i++)
	{
		for (int j=0;j<m;j++)
			fin>>a[i][j];
	}
	int max =0;
	int tot;
	int ln;
	for (int i=0;i<pow(2,m);i++)
	{
		//cout<<"--"<<i<<"--"<<endl;
		int mask = 1;
		int mult;
		for (int j =0; j<m; j++)
		{
			if ((i & mask) != 0)
				mult = 1;
			else 
				mult = -1;
			for (int k =0; k<n; k++)
				b[k][j] = a[k][j]*mult;
			mask<<=1;
		}
		tot = 0;
		for (int j=0;j<n;j++)
		{
			ln = 0;
			for (int k=0;k<m;k++)
			{
				ln+=b[j][k];
			}
			tot+=abs(ln);
			//cout<<abs(ln)<<endl;
		}
		if (tot>max)
			max = tot;
	}
	fout<<max<<endl;
	fin.close();
	fout.close();
	return 0;
}