#include <fstream>
#include <algorithm>
using namespace std;
 
ifstream is ("flip.in");
ofstream os ("flip.out");
 
int a[17][17];
int smax;
 
int main()
{
    short n, m;
    long i ,j, k, s, t;
    is >> n >> m;
    for ( i = 0; i < n; i++ )
        for ( j = 0; j < m; j++ )
            is >> a[i][j];
    for ( i = 0; i < ( 1 << m ); i++ )
    {
        s = 0;
        for ( k = 0; k < n; k++ )
        {
            for ( t = j = 0; j < m; j++ )
                if ( i & ( 1 << j ) )
                    t += -a[k][j];
            else
                t += a[k][j];
            s += t <- t ? - t:t;
        }
    if ( smax < s )
        smax = s;}
    os << smax;
    is.close();
    os.close();
    return 0;
}