#include<fstream.h>
ifstream f("flip.in"); ofstream g("flip.out");
int n,m,k,x[17];
long smax=0,a[17][17];
void prelsol()
{int i,j;
 long s=0,sc;
 for(j=1;j<=m;j++)
  {sc=0;
   for(i=1;i<=n;i++) if(x[i]) sc-=a[i][j]; else sc+=a[i][j];
   if(sc<0) s-=sc; else s+=sc;
  }
 if(s>smax) smax=s;
}
void back()
{k=1; x[k]=-1;
 do
  {while(x[k]<=0)
    {x[k]++;
     if(k==n) prelsol(); else x[++k]=-1;
    }
   k--;
  }
 while(k);
}
void cit()
{int i,j;
 f>>n>>m;
 for(i=1;i<=n;i++) for(j=1;j<=m;j++) {f>>a[i][j]; smax+=a[i][j];}
}
void afis()
{g<<smax<<'\n';
 g.close(); f.close();
}
int main()
{cit();
 back();
 afis();
 return 0;
}