#include<fstream>
using namespace std;
ifstream F("flip.in");
ofstream G("flip.out");
int a[17][17],s[17],b,n,m,i,j;
void B(int k)
{
    int i,c;
	if(k==n+1) {
		for(c=0,i=1;i<=m;++i)
			c+=abs(s[i]);
		b=max(b,c);
		return;
	}
	for(B(k+1),i=1;i<=m;++i)
		s[i]-=2*a[k][i];
	for(B(k+1),i=1;i<=m;++i)
		s[i]+=2*a[k][i];
}
int main()
{
    F>>n>>m;
    for(i=1;i<=n;++i) {
        for(j=1;j<=m;++j)
            F>>a[i][j],s[j]+=a[i][j];
    }
	B(1),G<<b;
	return 0;
}