#include<fstream>
using namespace std;
ifstream F("flip.in");
ofstream G("flip.out");
int a[16][16],s[16],b;
short n,m,i,j;
void B(short k)
{
    int c;
    short i;
	if(k==n) {
		for(c=0,i=0;i<m;c+=abs(s[i++]));
		b=max(b,c);
	} else {
        for(B(k+1),i=0;i<m;s[i]-=2*a[k][i],++i);
        for(B(k+1),i=0;i<m;s[i]+=2*a[k][i],++i);
	}
}
int main()
{
    for(F>>n>>m;i<n;++i)
        for(j=0;j<m;F>>a[i][j],s[j]+=a[i][j],++j);
	return B(0),G<<b,0;
}