#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

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

const int NMAX = 16;

int n, m;
int smax;
int v[1 + NMAX];
int a[1 + NMAX][1 + NMAX];

void solve() {
  int sumc;
  int sum = 0;

  for(int j = 1; j <= m; j++) {
    sumc = 0;
    for(int i = 1; i <= n; i++)
      sumc += a[i][j] * v[i];
    sum += abs(sumc);
  }
  smax = max(sum, smax);
}

void bkt(int k) {
  if(k == n + 1)
    solve();
  else {
    v[k] = 1;
    bkt(k + 1);

    v[k] = -1;
    bkt(k + 1);
  }
}

int main()
{
  in >> n >> m;
  for(int i = 1; i <= n; i++)
    for(int j = 1; j <= m; j++)
      in >> a[i][j];

  bkt(1);

  out << smax << '\n';

  in.close();
  out.close();
}