#include <fstream>
#include <math.h>
using namespace std;
int n,m,i,j,a[100][100],s[3];
int main()
{
    ifstream f("flip.in");
    ofstream g("flip.out");
    f >> n >> m;
    for(i = 0; i < n; i++)
        for(j = 0; j < m; j++)
            f >> a[i][j];
    for(i = 0; i < n; i++)
    {
        s[0] = s[1] = 0;
        for(j = 0; j < m; j++)
        {
            s[0] += a[i][j];
            s[1] += a[i][j] * -1;
        }
        if(s[1] > s[0])
            for(j = 0; j < m; j++)
                a[i][j] *= -1;
    }
    for(j = 0; j < m; j++)
    {
        s[0] = s[1] = 0;
        for(i = 0; i < n; i++)
        {
            s[0] += a[i][j];
            s[1] += a[i][j] * -1;
        }
        if(s[1] > s[0])
            for(i = 0; i < n; i++)
                a[i][j] *= -1;
    }
    for(i = 0; i < n; i++)
        for(j = 0; j < m; j++)
            s[2] += a[i][j];
    g << s[2];
    g.close();
    return 0;
}