#include <fstream>
using namespace std;
ifstream cin("flip.in");
ofstream cout("flip.out");
int n,m,i,j,a[17][17],Max;
bool b[17];
int main()
{
    cin>>n>>m;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            cin>>a[i][j];
    while(b[0]==0){
        int k=n,s=0;
        while(b[k]==1)
            b[k--]=0;
        b[k]=1; /// schimb semnul pe linia k
        if(b[0]!=0)
            break;
        for(j=1;j<=m;j++){
            int sum=0;
            for(i=1;i<=n;i++) /// fac suma coloanei j
                if(b[i]==0)
                    sum+=a[i][j];
                else
                    sum-=a[i][j];
            if(sum>0)
                s+=sum;
            else
                s-=sum;/// schimb semnele pe coloana i
        }
        Max=max(Max,s);
    }
    cout<<Max;
    return 0;
}