#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int n,m,mat[20][20],col[20],lin[20],S,St,Smx;
void bk(int i){
    if(i>m)
    {
        St=0;
        for(int l=1;l<=n;l++)
            {
            S=0;
            for(int c=1;c<=m;c++)
                    if(col[c]==1)
                        S=S-mat[l][c];
                    else S=S+mat[l][c];
            if(S<0)
                S=-S;
            St=St+S;
            }
        if(St>Smx)
            Smx=St;
        return;
    }
    col[i]=1;
    bk(i+1);
    col[i]=0;
    bk(i+1);

}
int main()
{
    ///Faci bk la coloane
    ///dupa iei partea optima de generare pe linii
    fin>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            fin>>mat[i][j];
    bk(1);
    fout<<Smx;
    return 0;
}