#include <iostream>
#include <fstream>

using namespace std;

#define MAX 17

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

int b[MAX][MAX],a[MAX];
int maxsum,s,n,m;

void do_stuff()
{
    int i,j;
    s=0;
    for(i=1;i<=n;i++)
    {
        int sum_that_does_something_important=0;
        for(j=1;j<=m;j++)
        {
            sum_that_does_something_important+=b[i][j]*a[j];
        }
        s+=max(sum_that_does_something_important, -sum_that_does_something_important);
    }
    maxsum=max(maxsum, s);
}

void bek(int k)
{
    if(k==m+1)
    {
        do_stuff();
        return;
    }
    a[k]=-1;
    bek(k+1);
    a[k]=1;
    bek(k+1);
}

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

    bek(1);
    fout<<maxsum<<endl;
    fin.close();
    fout.close();
    return 0;
}