#include <fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int main ()
{
    long int m, n, a[17][17], max, s = 0, t, j, i, k;
    fin >> m;
    fin >> n;
    for ( i = 0; i < n; i++ )
    for ( j = 0; j < m; j++ )
    fin >> a[i][j];
    for ( i = 0; i < ( 1 << m ); i++ )
    {
        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 ( max < s )
        max = s;
    }
    fout << max;
    fin.close();
    fout.close();
    return 0;
}