#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n;
  cin >> n;
  vector<long long> x(2 * n - 1);
  for (long long p = 0; p < 2 * n - 1; ++p) cin >> x[p];
  long long count = 0;
  for (const auto &i : x) {
    if (i < 0) count++;
  }
  if (n % 2 != 0) {
    long long ans = 0;
    for (const auto &i : x) {
      ans += abs(i);
    }
    cout << ans << '\n';
  } else {
    long long ans = 0;
    long long minX = 1000000009;
    for (const auto &i : x) {
      ans += abs(i);
      minX = min(minX, abs(i));
    }
    if (count % 2 != 0) {
      cout << ans - 2 * minX << '\n';
    } else {
      cout << ans << '\n';
    }
  }
}
signed main(signed argc, char **argv) {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  if (argc > 1 && (string)argv[1] == "local") {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    solve();
    while (cin.peek() != EOF) {
      cout << "\n\n";
      solve();
    }
  } else {
    solve();
  }
}
