#include <fstream>
using namespace std;

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

long long v[20][20],Max=-1000000005,semn[20];
int n,m;

int sum()
{
    long long sum=0,s = 0;
    for (int i = 1; i<=n; i++)
    {
        s = 0;
        for (int j = 1; j<=m; j++)
        {
            if (semn[j])
                s-=v[i][j];
            else
                s+=v[i][j];
        }
        if (s>0)
            sum+=s;
        else
            sum-=s;
    }
    return sum;
}

void Back(int k)
{
    if (k>m)
    {
        if (sum()>Max)
            Max = sum();
        return;
    }
    semn[k] = 0;
    Back(k+1);
    semn[k] = 1;
    Back(k+1);
}

int main()
{
    in >> n >> m;
    for (int i =1; i<=n; i++)
        for (int j=1; j<=m; j++)
            in >> v[i][j];
    Back(1);
    out << Max;
}