#include <fstream>
using namespace std;
ifstream in("flip.in");
ofstream out("flip.out");
const int N = 17, M = 17;
int a[N][M] , x[N] , n , m , maxp , maxt;
int s()
{
    int maxp = 0;
    for(int i=1;i<=m;i++)
    {
        int s = 0;
        for(int j=1;j<=n;j++)
        {
            int y = a[j][i];
            if(x[j] == 0) y = -y;
            s+=y;
        }
            if(s< 0 )
                s=-s;
            maxp +=s;
      }

    if(maxp > maxt ) maxt = maxp;
}
int backtracking(int k)
{
    for(int i=0;i<=1;i++)
    {
        x[k] = i;
        if(k==n) s();
            else
            backtracking(k+1);
    }
}
int main()
{
    in >> n >> m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            {
                in >> a[i][j];
            }
    backtracking(1);
    out << maxt;
    return 0;
}