#include <bits/stdc++.h>
using namespace std;
int N, M;
int cnt[1100];
set<pair<int, int> > avb;
void dfs(pair<int, int> vr) {
  if (avb.count(vr)) return;
  avb.insert(vr);
  for (int take = 0; take <= N; ++take) {
    int L = take, R = N - take;
    if (L > vr.first || R > vr.second) continue;
    dfs(make_pair(vr.first - L + R, vr.second + L - R));
  }
}
int main() {
  scanf("%d", &N);
  M = 2 * N - 1;
  dfs(make_pair(0, M));
  for (int i = 0; i < M; ++i) scanf("%d", &cnt[i]);
  sort(cnt, cnt + M);
  int BS = -1000000000;
  for (set<pair<int, int> >::iterator it = avb.begin(); it != avb.end(); ++it) {
    int L = it->first, R = it->second;
    int cs = 0;
    for (int i = 0; i < L; ++i) cs -= cnt[i];
    for (int i = L; i < L + R; ++i) cs += cnt[i];
    (BS) = max((BS), (cs));
  }
  cout << BS << '\n';
  return 0;
}
