#include <iostream>
#include <fstream>

using namespace std;
typedef long long int ll;
#define forn(i,e) for(ll i = 0 ; i < e; i++)
ll mat[17][17];
ll x[17];
ll n , m;
ll nmax = 0;
ifstream f("flip.in");
ofstream g("flip.out");
void bkt(short val){
    if(val < n) {
        x[val] = 1;
        bkt(val + 1);
        x[val] = -1;
        bkt(val + 1);
    }else{
        ll s = 0;
        forn(j,m){
            ll col = 0;
            forn(i,n){
                col += x[i] * mat[i][j];
            }
            col = max(col,-col);
            s += col;

        }
        nmax = max(s,nmax);
    }
}
int main(){

    f >> n >> m;
    forn(i,n){
        forn(j,m){
            f >> mat[i][j];
        }
    }
    bkt(0);
    g << nmax;
    return 0;



}