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

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

int val[17], mat[17][17];
int n,m;
long long maxsum, sum, sumcol;

void bkt(int it) {
    if(it > m) {
        sum = 0;
        for(int i = 1; i <= n; i++) {
            sumcol = 0;
            for(int j = 1; j <= m; j++) {
                sumcol += val[j] * mat[i][j];
            }
            if(sumcol < 0) {
                sumcol = -sumcol;
            }
            sum += sumcol;
        }
        maxsum = max(maxsum, sum);
    } else {
        val[it] = 1;
        bkt(it + 1);
        val[it] = -1;
        bkt(it + 1);
    }
}

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

    bkt(1);
    fout << maxsum << " ";
}