#include <cstdio>
using namespace std;
int a[20][20],flip[20];
int p2(int k)
{
    int nr=1;
    while(k)
        nr*=2,k--;
    return nr;
}
int main()
{
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    int n,m,i,j,mx=-2000000000,p,s,sum;
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
                scanf("%d",&a[i][j]);
    int p2n=p2(n);
    for(p=0;p<p2n;p++)
    {
        sum=0;
        for(i=1;i<=n;i++)
        if(p&(p2(i-1)))
            flip[i]=-1;
        else flip[i]=1;
        for(j=1;j<=m;j++)
        {
            s=0;
            for(i=1;i<=n;i++)
                    s+=a[i][j]*flip[i];
            if(s>=0)
                sum+=s;
            else sum-=s;
        }
        if(sum>mx)
            mx=sum;
    }
    printf("%d",mx);

    return 0;
}