#include <fstream>
#include <iostream>

using namespace std;
 
ifstream in("flip.in");
ofstream out("flip.out");
int n,m,i,j,v[20][20],b[20],smax,s1,s;
int main()
{
    in>>n>>m;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            in>>v[i][j];
    while(b[0]==0)
    {
        s1=0;
        for(i=1;i<=n;i++)
        {
            s=0;
            for(j=1;j<=m;j++)
            {
                if(b[j]==0)
                    s=s+v[i][j];
                else
                    s=s-v[i][j];
            }
            if(s<0)
                s1=s1-s;
            else
                s1=s1+s;
        }
        smax=max(smax,s1);
        for(i=m;b[i]==1;i--)
        {
            b[i]=0;
        }
        b[i]++;
    }
    out<<smax;
    return 0;
}