#include <cstdio>
#include <cmath>
#include <algorithm>
#define NMAX 20
using namespace std;
int a[NMAX][NMAX];
int main()
{
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    int n,m,i,j,nr_pos,smax=0,s,snow,k;
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;++i)
        for(j=1;j<=m;++j)
        {
            scanf("%d",&a[i][j]);
            smax+=a[i][j];
        }
    nr_pos=1<<(m-1);
    for(k=1;k<=nr_pos;++k)
    {
        s=0;
        for(i=1;i<=n;++i)
        {
            snow=0;
            for(j=1;j<=m;++j)
            {
                //printf("%d %d\n",k,1<<(j-1));
                if((k&(1<<(j-1)))==0)
                {
                    snow+=a[i][j];
                }
                else
                    snow-=a[i][j];
            }
            s+=abs(snow);
        }
        smax=max(smax,s);
    }
    printf("%d\n",smax);
    return 0;
}