#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
#define Nmax 20

ifstream f("flip.in");
ofstream g("flip.out");

int n,m,maxim,a[Nmax][Nmax],s[Nmax];

void ReadInput()
{
    f>>n>>m;
    for (int i=1;i<=n;i++)
        for (int j=1;j<=m;j++)f>>a[i][j];
}

void CalcSuma()
{
    int Total=0; // suma pe toata matricea
    for (int j=1;j<=m;j++)
    {
        int sum=0; // suma maxima pe coloane
        for (int i=1;i<=n;i++)
            if (s[i]) sum+=-a[i][j];
                 else sum+=a[i][j];
        if (sum<0) sum*=-1;
        Total+=sum;
        maxim=max(maxim,Total);
    }
}

void Back(int k) // fiecare permutare a sirului s este linia rasturnata
{
    if (k ==n+1) CalcSuma();
    else    for (int i = 0; i <= 1; ++i)
            {
                s[k]=i;
                Back(k+1);
            }
}

int main()
{
    ReadInput();
    Back(1);
    g<<maxim<<'\n';
    f.close();g.close();
    return 0;
}