#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;

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

    int N, M;
    fin >> N >> M;

    vector<vector<int>> A(N, vector<int>(M));
    for (int i = 0; i < N; ++i)
        for (int j = 0; j < M; ++j)
            fin >> A[i][j];

    int max_sum = INT_MIN;

   
    for (int mask = 0; mask < (1 << N); ++mask) {
       
        vector<vector<int>> B = A;
        for (int i = 0; i < N; ++i)
            if ((mask >> i) & 1) 
                for (int j = 0; j < M; ++j)
                    B[i][j] *= -1;

        int total = 0;
       
        for (int j = 0; j < M; ++j) {
            int col_sum = 0;
            for (int i = 0; i < N; ++i)
                col_sum += B[i][j];
           
            total += max(col_sum, -col_sum);
        }

        max_sum = max(max_sum, total);
    }

    fout << max_sum << "\n";

    return 0;
}