#include<fstream>
 
using namespace std;
long int i,j,m,n,k,aux,b[1000],a[100][100],smat,s,max=-1;
int main()
{
ifstream fin("flip.in");
ofstream fout("flip.out");
fin>>n;
fin>>m;
int max=-1;
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
fin>>a[i][j]; 
for(i=0;i<(1<<n);i++)
{
aux=i;
for(j=1;j<=n;j++)
{
b[j]=aux&1;
aux>>=1;
}
smat=0;
for(k=1;k<=m;k++)
{
s=0;
for(j=1;j<=n;j++)
{
if(b[j])
s+=a[j][k];
else s-=a[j][k];}
if(s<0)
smat-=s;
else smat+=s;
}
if(smat>max)
max=smat;
}
fout<<max;
}