#include <fstream>

using namespace std;

int v[17][17],a[17],i,sol,n,m,j;

fstream f,g;

void bkt(int i)
{
    if(i<=n)
    {
        a[i]=1;
        bkt(i+1);
        a[i]=-1;
        bkt(i+1);
    }
    else
    {
        int s1=0,s2;
        int j,k;
        for(k=1;k<=m;k++)
        {
            for(j=1,s2=0;j<=n;j++)s2+=v[j][k]*a[j];
            if(s2<0)s2*=-1;
            s1+=s2;
        }
        if(s1>sol)sol=s1;
    }
}

int main()
{
    f.open("flip.in",ios_base::in);
    g.open("flip.out",ios_base::out);
    f>>n>>m;
    for(i=1;i<=n;i++)for(j=1;j<=m;j++)f>>v[i][j];
    bkt(1);
    g<<sol;
}