#include <bits/stdc++.h>

using namespace std;

const int N_MAX = 17;

int n, m, solution;
int mat[N_MAX][N_MAX], st[N_MAX];

void read() {
    ifstream fin("flip.in");

    fin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            fin >> mat[i][j];
        }
    }

    fin.close();
}

void solve() {
    int total_sum = 0;
    for(int j = 1; j <= m; ++j){
        int part_sum = 0;
        for(int i = 1; i <= n; ++i) {
            part_sum += (st[i]) ? mat[i][j] : -mat[i][j];
        }

        part_sum = max (part_sum, -part_sum);
        total_sum += part_sum ;
    }

    solution = max (total_sum, solution);
}

void backt(int level){
    if (level == n + 1){
        solve();
        return;
    }

    for (int i = 0; i < 2; ++i){
        st[level] = i;
        backt(level + 1);
    }
}

void write() {
    ofstream fout("flip.out");

    fout << solution;

    fout.close();
}

int main() {
    read();
    backt(1);
    write();
    return 0;
}