#include <bits/stdc++.h>
using namespace std;
ifstream f("flip.in");
ofstream g("flip.out");
vector<vector<int>> v;
int n, m;
long long maxim = LLONG_MIN;
int main()
{
    f >> n >> m;
    v.resize(n, vector<int>(m));
    for (auto &i : v)
        for (auto &j : i)
            f >> j;
    for (long long t = 0; __builtin_popcount(t) != n + m; t++)
    {
        long long ax = 0;
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++)
                ax += v[i][j] * ((((1ll << (i)) & t) ^ ((1ll << (n + j)) & t)) ? -1 : 1);
        maxim = max(maxim, ax);
    }
    g << maxim;
    return 0;
}