#include <iostream>
#include <fstream>
using namespace std;
long n,m,a[16][16],smax;
 int main()
{
    long i,j,k,s,t;
    ifstream f("flip.in");
    ofstream g("flip.out");
    f>>n>>m;
    for(i=0;i<n;i++)for (j=0;j<m;j++)f>>a[i][j];
    for(i=0;i<(1<<m);i++){
            s=0;
    for(k=0;k<n;k++){for(t=j=0;j<m;j++)if(i&(1<<j))t+=-a[k][j];
    else t+=a[k][j];
   if(t<-t)s+=-t;else s+=t;
    if(smax<s)smax=s;
    }}
    g<<smax;
    f.close();g.close();


}