#include <iostream>
#include <fstream>

using namespace std;

ifstream f("flip.in");
ofstream g("flip.out");

int main()
{
    int n, m;
    f >> n >> m;
    int a[n + 1][m + 1];
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            f >> a[i][j];
        }
    }
    int suma_finala1 = 0;
    for (int i = 1; i <= n; i++) {
        int suma1 = 0;
        for (int j = 1; j <= m; j++) {
            suma1 += a[i][j];
        }
        int suma2 = 0;
        for (int j = 1; j <= m; j++) {
            suma2 = suma2 + a[i][j] * (-1);
        }
        for (int j = 1; j <= m; j++) {
            if (suma2 > suma1) {
                a[i][j] *= -1;
            }
            suma_finala1 += a[i][j];
        }
    }
    int suma_finala2 = 0;
    for (int j = 1; j <= m; j++) {
        int suma1 = 0;
        for (int i = 1; i <= n; i++) {
            suma1 += a[i][j];
        }
        int suma2 = 0;
        for (int i = 1; i <= n; i++) {
            suma2 = suma2 + a[i][j] * (-1);
        }
        for (int i = 1; i <= n; i++) {
            if (suma2 > suma1) {
                a[i][j] *= -1;
            }
            suma_finala2 += a[i][j];
        }
    }
    g << max(suma_finala1, suma_finala2);
    return 0;
}