#include <fstream>
using namespace std;
ifstream fi("flip.in");
ofstream fo("flip.out");
int n,m,A[20][20],maxi,S[20];
void sum()
{
    int s1,s2=0;
    for (int i=1; i<=n; i++)
    {
        s1=0;
        for (int j=1; j<=m; j++)
            s1=s1+S[j]*A[i][j];
        if (s1<0)
            s2=s2-s1;
        else
            s2=s2+s1;
    }
    if (s2>maxi)
        maxi=s2;
}
void backtrack(int k)
{
    if (k>m)
        sum();
    else
        for (int l=-1; l<=1; l++)
            if (l!=0)
            {
                S[k]=l;
                backtrack(k+1);
            }
}
int main()
{
    fi>>n>>m;
    for(int i=1; i<=n; i++)
        for(int j=1; j<=m; j++)
            fi>>A[i][j];
    backtrack(1);
    fo<<maxi;
}