#include <fstream>

using namespace std;

ifstream fin("flip.in");
ofstream fout("flip.out");

int n,m,i,j,a[20][20],b[20][20],v[20],s,sm,ans,x;

int main()
{
    fin>>n>>m;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            fin>>a[i][j];
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            b[i][j]=a[i][j]*(-1);
    while(!v[0])
    {
        sm=0;
        for(i=1;i<=n;i++)
        {
            s=0;
            for(j=1;j<=m;j++)
                {
                    if(v[j]==1)s+=b[i][j];
                    else s+=a[i][j];
                }
            if(s<0)s*=-1;
            sm+=s;
        }
        ans=max(ans,sm);
        x=m;
        v[x]++;
        while(v[x]==2)
        {
            v[x--]=0;
            v[x]++;
        }
    }
    fout<<ans;
    return 0;
}