#include<iostream>
#include<fstream>
#define FOR(a,b,c) for(a=b;a<=c;a++)
using namespace std;
int main()
{
	ifstream fin("flip.in");
	ofstream fout("flip.out");
	int n,m,a[17][17],i,j,k,s1,s2,max=0;
	fin>>n>>m;
	FOR (i,1,n)
		FOR (j,1,m)
			fin>>a[i][j];
	for (k=0;k<(1<<m);k++)
	{
		FOR (j,1,m)
			a[0][j] = (1<<j-1)&k?1:-1;
		s2 = 0;
		FOR (i,1,n)
		{
			s1 = 0;
			FOR (j,1,m)
				s1 += a[i][j]*a[0][j];
			s2 += s1>0?s1:-s1;
		}
		max = s2>max?s2:max;
	}
	fout<<max;
	fin.close();
	fout.close();
	return 0;
}