#include <iostream>
#include <fstream>
using namespace std;
int n, m, max_sum, v[16][16];
bool comute[16];
int Sum()
{
    int sum = 0, line_sum = 0;
    for(int j = 0; j < m; j++)
    {
        line_sum = 0;
        for(int i = 0; i < n; i++)
        {
            if(comute[i]) line_sum -= v[i][j];
            else line_sum += v[i][j];
        }
        if(line_sum < 0) sum-= line_sum;
        else sum+=line_sum;
    }
    return sum;
}
void Solve(int index)
{
    if(index > n - 1)
    {
        int s = Sum();
        if(s > max_sum)
            max_sum = s;
    }
    else
    {
        comute[index] = 0;
        Solve(index+1);
        comute[index] = 1;
        Solve(index+1);
    }
}
int main()
{
    ifstream in("flip.in");
    in >> n >> m;
    for(int i = 0; i < n; i++)
        for(int j = 0; j < m; j++)
            in>>v[i][j];
    in.close();
    Solve(0);
    ofstream out("flip.out");
    out <<max_sum;
    out.close();
    return 0;
}