#include <iostream>
#include <fstream>
using namespace std;
 
ifstream f("flip.in");
ofstream g("flip.out");
 
int n, m, sol;
int tabla[26][26];
int raspuns[26];
 
void verificare()
{
    int suma = 0;
    for(int i=1; i<=n; i++)
    {
        int s = 0;
        for(int j=1; j<=m; j++)
        {
            if(raspuns[j]) s = s-tabla[i][j];
            else s = s+tabla[i][j];
        }
        if(s < 0) suma = suma - s;
        else suma = suma + s;
    }
    if(suma > sol) sol = suma;
}
 
void backtracking(int k)
{
    if(k == m) verificare();
    else
    {
        for(int i=0; i<=1; i++)
        {
            raspuns[k] = i;
            backtracking(k+1);
        }
    }
}
 
int main()
{
    f>>n>>m;
    for(int i=1; i<=n; i++)
        for(int j=1; j<=m; j++)
            f>>tabla[i][j];
 
        backtracking(1);
        //cout<<endl<<"Solutia este "<<sol;
        g<<sol;
 
    cout<<endl;
    f.close();
    g.close();
    return 0;
}