#include<stdio.h>
int n,m,a[17][17],x[17],sol,sl,sm,i,j;
void back(int c)
{if(c==m+1)
  {sm=0;
  for(i=1;i<=n;i++)
    {sl=0;
    for(j=1;j<=m;j++)
      sl=sl+x[j]*a[i][j];
    sl=sl>=0?sl:-sl;
    sm=sm+sl;}
  if(sol<sm)
   sol=sm;
  return;}
    x[c]=1;back(c+1);
    x[c]=-1;back(c+1);
}
int main()
{freopen("flip.in","r",stdin);
freopen("flip.out","w",stdout);
scanf("%d%d",&n,&m);
for(i=1;i<=n;i++)
  for(j=1;j<=m;j++)
    scanf("%d",&a[i][j]);
x[1]=1;
    back(2);
    printf("%d\n",sol);
return 0;}