#include <fstream>
#include <iostream>
#include <cmath>
using namespace std;
ifstream in("flip.in");
ofstream out("flip.out");
int a[17][17], f[17], n, m, maxim;

void check() {
    int s = 0;
    for(int j = 1; j <= m; j++) {
        int sc = 0;
        for(int i = 1; i <= n; i++)
            sc += a[i][j] * f[i];
        s += abs(sc);
        maxim = max(maxim, s);
    }
}
void backt(int k) {
    if(k <= n) {
        f[k] = 1;
        backt(k+1);
        f[k] = -1;
        backt(k+1);
    } else check();
}
int main()
{
    in >> n >> m;
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= m; j++)
            in >> a[i][j];

    backt(1);
    out << maxim;
    return 0;
}