#include <fstream>
using namespace std;

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

int n, m, sum, s, sol;
int a[20][20];

int main(){
    fin >> n >> m;
    for(int i = 1; i <= n; i++)
        for(int j = 1;j <= m; j++)
            fin >> a[i][j];
    for (int masca = 0; masca <= (1<<m) - 1; masca++) {
        sum = 0;
        for (int i = 1; i <= n; i++) {
            s = 0;
            for (int j = 1; j <= m; j++ ){
                if ( ((masca>>j) & 1) == 0 )
                    s += a[i][j];
                else
                    s -= a[i][j];
            }
            if ( s > 0 )
                sum += s;
            else
                sum -= s;
        }
        if (sol < sum)
            sol = sum;
    }
    fout << sol;
    return 0;
}