#include <fstream>
#define VAL 25

using namespace std;

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

int N, M, i, j;
int v[VAL][VAL];
int c[VAL], s;
int sc, sum, mx;

int rezolvare()
{
    for (i=1; i<=M; i++)
    {
        if (c[i]==1)
          c[i]=0, s--;
        else
        {
            c[i]=1;
            s++;
            break;
        }
    }
    sum=0;
    for (i=1; i<=N; i++)
    {
        sc=0;
        for (j=1; j<=M; j++)
        {
            if (c[j]==1)
              sc-=v[i][j];
            else
              sc+=v[i][j];
        }
        if (sc<0)
          sc*=-1;
        sum+=sc;
    }
    mx=max(mx, sum);
    if (s<M)
      rezolvare();
    else
      return mx;
}

int main()
{
    fin >> N >> M;
    for (i=1; i<=N; i++)
      for (j=1; j<=M; j++)
        fin >> v[i][j];
    fout << rezolvare() << '\n';
    fin.close();
    fout.close();
    return 0;
}