#include <fstream>
using namespace std;
int n, m, i, j, S, suma, maxim;
int a[17][17], col[17];

int main () {
    ifstream fin ("flip.in");
    ofstream fout ("flip.out");
    fin>>n>>m;

    for (i=1;i<=n;i++)
        for (j=1;j<=m;j++)
            fin>>a[i][j];

    ///se iau toate variantele de comutare pentru fiecare coloana
    ///cele doua stari sunt 0 si 1

    while(col[0]==0){
            i=m;
            while(col[i]==1){
                col[i]=0;
                i--;
            }
            col[i]=1;

            S=0;
            for(i=1;i<=n;i++){
                suma=0;
                for(j=1;j<=m;j++){
                    if(col[j]==1)
                        suma+=a[i][j];
                    else
                        suma-=a[i][j];
                }
                if(suma<0)
                    S-=suma;
                else
                    S+=suma;
            }
            if(S>maxim)
                maxim=S;
    }

    fout<<maxim;

    return 0;
}