#include <iostream>
#include <fstream>
using namespace std;
ifstream ka("flip.in");
ofstream ki("flip.out");

const int N_MAX = 16;

int a[N_MAX][N_MAX], maximm, n, m;

int main()
{
    ka >> n >> m;
    for(int i = 0; i < n; i++)
        for(int j = 0; j < m; j++)
            ka >> a[i][j];
    int maxim = (1 << n);
    for(int c = 0 ; c < maxim; c++)
    {
        int total = 0;
        for(int j = 0; j < m; j++)
        {
            int s = 0;
            for(int i = 0; i < n; i++)
            {
                if((1 << i) & c)
                    s += (-1) * a[i][j];
                else
                    s += a[i][j];
            }
            if(s*(-1) > s)
                s *= (-1);
            total += s;
        }
        if(total > maximm)
            maximm = total;
    }
    ki << maximm;
}