#include <fstream>
#include <vector>
#include <climits>

using namespace std;
ifstream cin("flip.in");
ofstream cout("flip.out");
int n,m,v[20][20],sol=INT_MIN;
vector<int>linii;
void solve()
{
    for(int linie:linii)
    for(int j=1; j<=m; j++)
        v[linie][j]*=-1;
        int sum_total=0;
    for(int j=1; j<=m; j++)
    {
        int sum_col=0;
        for(int i=1; i<=n; i++)
            sum_col+=v[i][j];
        sum_total+=abs(sum_col);
    }
    sol=max(sol,sum_total);

    for(int linie:linii)
    for(int j=1; j<=m; j++)
        v[linie][j]*=-1;
}
void backtracking(int val)
{
    if(val>n)
    {
        solve();
        return;
    }
    else
    {
        linii.push_back(val+1);
        backtracking(val+1);
        linii.pop_back();
        backtracking(val+1);
    }
}
int main()
{
    cin>>n>>m;
    for(int i=1; i<=n; i++)
        for(int j=1; j<=m; j++)
            cin>>v[i][j];
    backtracking(1);
    cout<<sol;
    return 0;
}