#include <bits/stdc++.h>
#define int long long
#define ll long long
#define pb push_back
#define fi first
#define se second
#define pii pair<int, int>
#define mk make_pair
using namespace std;
const int MAXN = 5e5 + 5, INF = 1e9;

int n, len, num1, mst = 0;
int a[MAXN], mp[MAXN], fa[MAXN], si[MAXN];

void Make_set() {
	for (int i = 1; i <= n; i ++) 
		fa[i] = i, si[i] = 1;
}

int Find_set(int x) {
	return fa[x] == x ? x : fa[x] = Find_set(fa[x]);
}

bool cmp(int x, int y) {
	return a[x] == a[y] ? x > y : a[x] < a[y]; 
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
	cin >> n, len = 2 * n - 1;
	Make_set();
	for (int i = 3; i <= len; i ++) mp[i] = i;	
	for (int i = 3; i <= len; i ++) cin >> a[i];
	sort(mp + 3, mp + len + 1, cmp);
	for (int i = 3; i <= len; i ++){
		int num2 = 0;
		for (int j = max(1, mp[i] - n); j * 2 < mp[i]; j ++){
			int f1 = Find_set(j), f2 = Find_set(mp[i] - j);
			if (f1 == f2) num2 ++;
			else {
				if (si[f1] > si[f2]) swap(f1, f2);
				fa[f1] = f2, si[f2] += si[f1];
				mst += a[mp[i]];
			}
			num1 ++;
			if (num1 > 1e9 || (num2 > 1e3 && num1 >= 1e6)) break;
		}
	}
	printf("%d\n", mst);
    return 0;
}

answer.code: In function ‘int main()’:
answer.code:38:33: error: no matching function for call to ‘max(int, long long int)’
   38 |                 for (int j = max(1, mp[i] - n); j * 2 < mp[i]; j ++){
      |                              ~~~^~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from answer.code:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: ‘template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)’
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
answer.code:38:33: note:   deduced conflicting types for parameter ‘const _Tp’ (‘int’ and ‘long long int’)
   38 |                 for (int j = max(1, mp[i] - n); j * 2 < mp[i]; j ++){
      |                              ~~~^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: ‘template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)’
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5705:5: note: candidate: ‘template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)’
 5705 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5705:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5715:5: note: candidate: ‘template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)’
 5715 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5715:5: note:   template argument deduction/substitution failed:
answer.code:38:33: note:   mismatched types ‘std::initializer_list<_Tp>’ and ‘int’
   38 |                 for (int j = max(1, mp[i] - n); j * 2 < mp[i]; j ++){
      |                              ~~~^~~~~~~~~~~~~~
answer.code:50:18: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘long long int’ [-Wformat=]
   50 |         printf("%d\n", mst);
      |                 ~^     ~~~
      |                  |     |
      |                  int   long long int
      |                 %lld