#include <iostream>
#include <fstream>
  
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int i,j,n,m,a[20][20], maxim=0, s[20];
  
  
void sum()
{
    int ss,st=0;
    for (i=1;i<=n;i++)
    {
        ss=0;
        for (j=1;j<=m;j++)
            ss+=s[j]*a[i][j];
        if (ss<0) st=st-ss;
            else st+=ss;
    }
    if (st>maxim) maxim=st;
     
}
 
void back(int k)
{
    int l;
    if (k>m) sum();
    else
    for (l=-1;l<=1;l++)
    if (l!=0) {s[k]=l;back(k+1);}
}
 
int main()
{
fin>>n>>m;
for(i=1;i<=n;i++)
for(j=1;j<=m;j++)
fin>>a[i][j];
back(1);
fout<<maxim;
fin.close();
fout.close();
return 0;
}