#include <iostream>
#include <fstream>
#include <cmath>
#define Maxx 25
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int n,m,A[Maxx][Maxx],sol[Maxx*Maxx],i,j,ans=0,mat;
void get_sum()
{
    int tot=0,sum=0;
    for (int i=1;i<=n;i++)
    {
        sum=0;
        for (int j=1;j<=m;j++)
            sum+=sol[j]*A[i][j];
        tot+=abs(sum);
    }
    ans=max(tot,ans);
}
void bk(int k)
{
    if (k<=n || k<=m)
    {
        sol[k]=1;
        bk(k+1);
        sol[k]=-1;
        bk(k+1);
    }
    else
        get_sum();
}
int main()
{
    fin>>n>>m;
    for (i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            fin>>A[i][j];
    bk(1);
    fout<<ans;
    return 0;
}