#include <iostream>
#include <fstream>
using namespace std;
int a[20][20],i,j,k,s,m,n,st,solutie;
int main()
{
    ifstream f("flip.in");
    ofstream g("flip.out");
    f>>n>>m;
    for (i=1;i<=n;++i)
        for (j=1;j<=m;++j)
        f>>a[i][j];
    for (k=1;k<=(1<<m);++k)
    {
        st=0;
        for (i=1;i<=n;++i)
        {
            s=0;
            for (j=1;j<=m;++j)
            {
                if (k&&(1<<j)) s=s-a[i][j];
                else s=s+a[i][j];
            }
            if (s<-s) s=-s;
            st+=s;
        }
        solutie=max(st,solutie);
    }
    g<<solutie;
    return 0;
}