#include <bits/stdc++.h>
using namespace std;

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

int n, m, mat[20][20], sol[20], ans;

int Scor() {
    int sum = 0;
    for (int j = 1; j <= m; ++j) {
        int s = 0;
        for (int i = 1; i <= n; ++i) {
            s += (sol[i-1] ? -mat[i][j] : mat[i][j]);
        }
        sum += abs(s);
    }
    return sum;
}

void solve() {
    for (int k = 0; k < (1 << n); ++k) {
        for (int i = 0; i < n; ++i) {
            sol[i] = (k & (1 << i)) ? 1 : 0;
        }
        ans = max(ans, Scor());
    }
}

int main() {
    fin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            fin >> mat[i][j];
        }
    }
    solve();
    fout << ans;
    return 0;
}