#include    <iostream>
#include    <fstream>

using namespace std;

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

int N, M, map[20][20], sign[20], best;

int max(int a, int b)
{
    if(a > b)
        return a;
    return b;
}
void read()
{
    fin >> N >> M;
    for(int i = 1; i <= N; i++)
    {
        for(int j = 1; j <= M; j++)
        {
            fin >> map[i][j];
        }
    }
}

void solve()
{
    long nr, sum = 0;
    for(int i = 1; i <= N; i++)
    {
        nr = 0;
        for(int j = 1; j <= M; j++)
            nr += map[i][j] * sign[j];
        sum += max(nr,-nr);
    }
    best = max(best,sum);
}

void backtrack(int k)
{
    if(k == M + 1)
    {
        solve();
        return;
    }
    sign[k] = -1;
    backtrack(k + 1);
    sign[k] = 1;
    backtrack(k + 1);
}

int main()
{
    read();
    backtrack(1);
    fout << best;
    return 0;
}