#include <cstdio>
#define BIT(k) (1<<(k))
#define max(a, b) (a>b?a:b)

using namespace std;

int nl, nc;
int mat[20][20];
int scol[20], sc, smax = -1000000000;

int main()
{
    int i, j, c;
    freopen("flip.in", "r", stdin);
    freopen("flip.out", "w", stdout);
    scanf("%d%d", &nl, &nc);
    for(i = 0; i < nl; i++)
    {
        for(j = 0; j < nc; j++)
        {
            scanf("%d", &mat[i][j]);
        }
    }
    for(c = 0; c < BIT(nl); c++)
    {
        sc = 0;
        for(j = 0; j < nc; j++)
        {
            scol[j] = 0;
            for(i = 0; i < nl; i++)
            {
                if((c & BIT(i)) != 0)
                {
                    sc -= mat[i][j];
                    scol[j] -= mat[i][j];
                }
                else
                {
                    sc += mat[i][j];
                    scol[j] += mat[i][j];
                }
            }
        }
        for(j = 0; j < nc; j++)
        {
            if(scol[j] < 0) sc -= 2 * scol[j];
        }
        smax = max(smax, sc);
    }
    printf("%d", smax);
    return 0;
}