#include <bits/stdc++.h>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int sol[20],a[20][20],n,m,maxim,sum,col;

void Verif()
{
    int i,j;
    sum=0;///suma dintr-o matrice actionata
    for(j=1;j<=m;j++)
    {
        col=0;///Suma de pe coloane dupa ce am actionat comutatoarele
        for(i=1;i<=n;i++)
            if(sol[i]==1)col+=a[i][j]*(-1);
            else col+=a[i][j];
       if(col<col*(-1))sum+=col*(-1);
       else sum+=col;
    }
    maxim=max(sum,maxim);
}

void Back(int top)
{
    if(top==n)Verif();
    else for(int i=0;i<=1;i++)
    {
        sol[top]=i;
        Back(top+1);
    }
}

int main()
{
    int i,j;
    fin>>n>>m;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            fin>>a[i][j];
    Back(1);
    fout<<maxim;
    return 0;
}