#include <fstream>
#include <cstring>

#define maxn 20

using namespace std;

int n, m;
int initialSum = 0;
int mat[maxn][maxn];
int sumPerLine[maxn];
ifstream in("flip.in");

void read() {
    in >> n >> m;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++) {
            in >> mat[i][j];
            sumPerLine[i] += mat[i][j];
            initialSum += mat[i][j];
        }
}

int main() {

    read();
    int best = initialSum;
    int currentSum;
    int currentLine[maxn];

    for (int i = 1; i < 1 << m; i++) {
        memcpy(currentLine, sumPerLine, (n + 1) * sizeof(int));
        for (int j = 0; j < 32; j++) {
            if (i & (1 << j)) {
                for (int k = 1; k <= n; k++) {
                    currentLine[k] += -2 * mat[k][j+1];
                }
            }
        }

        currentSum = 0;
        for (int k = 1; k <= n; k++) {

            if (currentLine[k] < 0)
                currentSum -= currentLine[k];
            else
                currentSum += currentLine[k];
        }

        if (currentSum > best)
            best = currentSum;
    }

    ofstream out("flip.out");
    out << best;
    return 0;
}