#include <iostream>
#include <fstream>

using namespace std;

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

int short n, m;
int mat[20][20], a[40], maxVal = 0;

void sol()
{
    int fs = 0, ss;
    for(int i = 1; i <= m; i++)
    {
        ss = 0;
        for(int j = 1; j <= n; j++)
            ss += a[j] * mat[j][i];
        if(ss < 0)
            ss = -ss;

        fs += ss;
    }

    if(fs > maxVal) maxVal = fs;
}

void bktr(int i)
{
    if(i > n) sol();
    else {
        a[i] = 1;
        bktr(i + 1);
        a[i] = -1;
        bktr(i + 1);
    }
}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= m; j++)
            fin >> mat[i][j];

    bktr(1);
    fout << maxVal;

    return 0;
}