#include<cstdio>
int a[17][17];
int main()
{
 int n,m,i,j,max,cj,stot,s,k;
 freopen("flip.in","r",stdin);
 freopen("flip.out","w",stdout);
 scanf("%d%d",&n,&m);
 stot=0;
 for(i=0;i<n;i++)
    {
     for(j=0;j<m;j++)
        {
         scanf("%d",&a[i][j]);
        }
    }
 max=0;
 //1<<m = 2^m
 for(k=0;k<1<<m;k++)
    {
     stot=0;
     for(i=0;i<n;i++)
        {
         s=0;
         for(j=0;j<m;j++)
            {
             if(k&(1<<j))
                s-=a[i][j];
             else
                s+=a[i][j];
            }
         if(s<0)
            stot-=s;
         else
            stot+=s;
        }
     if(stot>max)
        max=stot;
    }
 printf("%d\n",max);
return 0;
}