#include <cstdio>

int k[19],n=0,m=0,v[19][19],max=-99999999;

int f(int x)
{
    int i,j,s,sf;
    if (x==m+1)
    {
        s=0;
        sf=0;
        for (i=1; i<n+1; ++i)
        {
            s=0;
            for (j=1; j<m+1; ++j)
                if (k[j]==1)
                    s-=v[i][j];
                else
                    s+=v[i][j];
            if (s<0)
                sf-=s;
            else
                sf+=s;
        }
        if (sf>max)
            max=sf;
    }
    else
        for (i=0; i<2; ++i)
        {
            k[x]=i;
            f(x+1);
        }
}

int main()
{
    int i=0,j=0;
    freopen("flip.in","r",stdin);
    freopen("flip.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (i=1; i<n+1; ++i)
        for (j=1; j<m+1; ++j)
            scanf("%d",&v[i][j]);
    f(1);
    printf("%d\n",max);
    return 0;
}