#include <iostream>
#include <fstream>

using namespace std;

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

int a[20][20], b[20], i, j, y, n, m, k, s, x;

int main()
{
    in >> n >> m;
    for(i = 1; i <= n; ++ i)
    {
        for(j = 1; j <= m; ++ j)
        {
            in >> a[i][j];
            k += a[i][j];
        }
    }

    for(i = 1; i <= (1 << n); ++ i)
    {
        x = 0;
        for(j = 1; j <= m; ++ j)
        {
            s = 0;
            for(y = 1; y <= n; ++ y)
            {
                if((i & (1 << y)) == 0)
                {
                    s += a[y][j];
                }
                else
                {
                    s -= a[y][j];
                }
            }
            x += max(s, -s);
        }
        k = max(k, x);
    }
    out << k;
    return 0;
}