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