#include <fstream>

using namespace std;

ifstream in ("flip.in");
ofstream out ("flip.out");

int n, m;

int v[20][20];

int p, s, ms, ans;

int main()
{
    in >> n >> m;
    for ( register int i = 1 ; i <= n ; ++i )
        for ( register int j = 1 ; j <= m ; ++j )
            in >> v[i][j];
    p = ( 1 << m );
    for ( register int q = 0 ; q <= p ; ++q )
    {
        ms = 0;
        for ( register int i = 1 ; i <= n ; ++i )
        {
            s = 0;
            for ( register int j = 1 ; j <= m ; ++j )
                if ( q & ( 1 << ( j - 1 ) ) )
                    s += v[i][j] * -1;
                else
                    s += v[i][j];
            if ( s < 0 )
                s *= -1;
            ms += s;
        }
        ans = max ( ans, ms );
    }
    out << ans;
    return 0;
}