#include <fstream>
#define lim 16
using namespace std;
int n, m, sw[lim], Mat[lim][lim], Sol, i, j;
void test()
{
    int i,j, S=0;
    for(i=0;i<n;i++){
        int s=0;
        for(j=0;j<m;j++){
           if(sw[j]) s-=Mat[i][j];
           else s+=Mat[i][j];
       }
       if(s<0) S-=s;
       else S+=s;
    }
    if(Sol<S) Sol = S;

}
void eval(int k)
{
    if(k==m-1)
        test();
    else{
        for(int i = 0;i <= 1; i++){
          sw[k]=i;
          eval(k+1);
        }
   }
}

int main()
{
    ifstream in("flip.in");
    ofstream out("flip.out");
    in>>n>>m;
    for(i=0;i<n;i++)
        for(j=0;j<m;j++)
           in>>Mat[i][j];
    eval(0);
    out<<Sol;
    in.close();
    out.close();
    return 0;
}