#include <bits/stdc++.h>
#define ll long long
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
int n, m, rez = -1e6, mt[20][20];

void solve(vector <int> v) {
    int sum = 0;
    for (int i = 1; i <= n; ++i) {
        int sumaux = 0, sumaux2 = 0;
        for (int j = 1; j <= m; ++j) {
            if (v[j] == 1)
                sumaux += -mt[i][j], sumaux2 += mt[i][j];
            else
                sumaux += mt[i][j], sumaux2 += -mt[i][j];
        }
        sum += max(sumaux, sumaux2);
    }
    rez = max(rez, sum);
    return;
}

void back(int pos, vector <int> v) {
    if (pos == m) {
        solve(v);
        return;
    }
    back(pos + 1, v);
    v[pos + 1] = 1;
    back(pos + 1, v);
    return;
}

int main() {
    fin >> n >> m;
    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= m; ++j)
            fin >> mt[i][j];
    vector <int> v(20);
    back(0, v);
    fout << rez;
    return 0;
}