#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

ifstream fin ("flip.in");
ofstream fout ("flip.out");

pair <int , int> lin [20], col [20];
int s[17][17];

int main() {
    int n,m;
    fin >> n >> m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            int x;
            fin >> x;
            s[i][j] = x;
            lin[i].first += x;
            lin[i].second = i;
            col[j].first += x;
            col[j].second = j;
        }
    }
    int ok = 0, k = 1;
    long long sum = 0;
    for (int i = 1; i <= m; i++) {
        if (col[i].first < 0) {
            col[i].first *= -1;
            for (int j = 1; j <= n; j++) {
                lin[j].first -= 2 * s[j][i];
            }
        }
        sum += col[i].first;
    }
    for (int i = 1; i <= n; i++) {
        //fout << lin[i].first<< "\n";
    }
    long long sum1 = 0, maxsum = -20000000000;
    for (int mask = 0; mask < (1 << n); mask++) {
        sum1 = 0;
        for (int i = 0; i < n; i++) {
            if (mask & (1 << i)) {
                sum1 += lin[i + 1].first * -1;
            }
            else {
                sum1 += lin[i + 1].first;
            }
            //fout << sum1 << "\n";
            maxsum = max(maxsum, sum1);
        }
    }
    fout << maxsum;
}