#include <fstream>

using namespace std;

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

int n, m;
int mat[17][17];
bool sol[17];
int smax = -2147483647;

void prelucrare() {
    int stot = 0;
    for(int i = 0; i < n; i++) {
        int sl = 0;
        for(int j = 0; j < m; j++) {
            if(sol[j])
                sl -= mat[i][j];
            else
                sl += mat[i][j];
        }
        if(sl < 0)
            sl = -sl;
        stot += sl;
    }
    if(stot > smax)
        smax = stot;
}

void backtrack(int p) {
    if(p == m) {
        prelucrare();
        return;
    }
    sol[p] = false;
    backtrack(p+1);
    sol[p] = true;
    backtrack(p+1);
}

int main() {
    in>>n>>m;

    for(int i = 0; i < n; i++)
        for(int j = 0; j < m; j++)
            in>>mat[i][j];

    backtrack(0);
    out<<smax;

    return 0;
}