#include <iostream>
#include <fstream>

using namespace std;
ifstream fin ("flip.in");
ofstream fout ("flip.out");
const int Nmax = 16;


int n, m, mat[Nmax][Nmax], config[Nmax], sol;
void rec(int niv){
    if (niv<n){
        config[niv]=1;
        rec(niv+1);
        config[niv]=-1;
        rec(niv+1);
    }
    else{
        int sum0, sum1, sumt=0;
        for (int j=0; j<m; j++){
            sum0=sum1=0;
            for (int i=0; i<n; i++){
                sum0+=config[i]*mat[i][j];
                sum1+=(0-config[i])*mat[i][j];
            }
            sumt+=max(sum0, sum1);
        }
        if (sumt>sol)
            sol=sumt;
    }
}
int main()
{
    fin>>n>>m;
    for (int i=0; i<n; i++)
        for (int j=0; j<m; j++)
            fin>>mat[i][j];
    rec(0);
    fout<<sol;
    return 0;
}