#include <bits/stdc++.h>

using namespace std;
int k[18][18];
int main() {
  ifstream cin("flip.in");
  ofstream cout("flip.out");
  int n, m;
  cin >> n >> m;
  int v[n + 1][m + 1];
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      cin >> v[i][j];
    }
  }
  long long mx = 0;
  for (int i = 0; i <= (1 << n); i++) {
    long long id = i;
    for (int j = 1; j <= n; j++) {
      if (id & 1) {
        for (int ii = 1; ii <= m; ii++)
          k[j][ii] = -v[j][ii];
      } else {
        for (int ii = 1; ii <= m; ii++)
          k[j][ii] = v[j][ii];
      }
      id = id >> 1;
    }
    long long res = 0;
    for (int i = 1; i <= m; i++) {
      long long c = 0;
      for (int j = 1; j <= n; j++) {
        c += k[j][i];
      }
      res += max(c, abs(-c));
    }
    mx = max(mx, res);
  }
  cout << mx;
}