#include <iostream>
#include <fstream>
using namespace std;
ifstream in("flip.in");
ofstream out("flip.out");
int v[16][16];
bool comutator[16];
int max_sum;
int n, m;
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(comutator[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
    {
        comutator[index] = 0;
        solve(index+1);
        comutator[index] = 1;
        solve(index+1);
    }
}
int main()
{

    in >> n >> m;
    for(int i = 0; i < n; i++)
        for(int j = 0; j < m; j++)
            in>>v[i][j];
    solve(0);
    out <<max_sum;
    return 0;
}