#include <bits/stdc++.h>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
int n, m, S = -256000010 , nr, a[17][17];
void suma(), Bk(int), transformare(int);
int main()
{
    f >> n >> m;
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= m; j++)
            f >> a[i][j];
    Bk(1);
    g << S;
    return 0;
}
void suma()
{
    int temp_s = 0;
    for(int i = 1; i <= n; i++)
    {
        int s = 0;
        for(int j = 1; j <= m; j++)
            s += a[i][j];
        if(s < 0)
            s = -s;
        temp_s += s;
    }
    S = max(S, temp_s);
}
void Bk(int col)
{
    if(col == m + 1)
    {
        suma();
        return;
    }
    Bk(col + 1);
    transformare(col);
    Bk(col + 1);
}
void transformare(int col)
{
    for(int i = 1; i <= n; i++)
        a[i][col] = -a[i][col];
}