#include<bits/stdc++.h>
using ll = long long;
using namespace std;
#define pll pair <ll,ll>
#define fi first
#define se second
#define sz(a) (ll((a).size()))
#define BIT(mask,i) (((mask) >> (i))&1)
#define MASK(i) (1LL << (i))
#define MP make_pair
namespace{
    const ll MAXN = 1e5;
    ll n;
    ll a[MAXN+100];
    ll b[MAXN+100];
    ll rev[MAXN+100];
    vector <pair <int,int> > ans;
    void solve(){
        set <ll> s;
        for (ll i = 1;i <= n;i ++)s.insert(i);
        for (ll i = 1;i <= n;i ++){b[i] = n + 1 - a[i];rev[b[i]] = i;}
        vector <ll> lds;
        ll inv[MAXN+100];
        while (sz(s)){
            vector <pll> tr;
            for (auto x:s){
                for (auto y:s){
                    if (x < y && a[x] < a[y]){
                        tr.push_back({x,y});
                    }
                }
            }
            pll best;
            ll cur_best = -1;
            ll single=*s.begin();
            for (auto i:s){
                inv[i] = 0;
                for (auto j:s){
                    ll l = min(i,j),r = max(i,j);
                    if (a[l] > a[r])inv[i]++;
                }
            }
            for (auto x:tr){
                ll sus = inv[x.fi] + inv[x.se] - (a[x.fi] > a[x.se]);
                if (sus > cur_best){
                    cur_best = sus;
                    best = x;
                }
            }
            for (auto x:s){
                if (inv[x] > inv[single])single = x;
            }
            if (cur_best != -1){
                s.erase(best.fi);
                s.erase(best.se);
                ans.push_back(MP(a[best.fi],a[best.se]));
            }
            else{
                s.erase(single);
                ans.push_back(MP(a[single],n+1));
            }
        }
        sort(ans.begin(),ans.end());
    }
}
std::vector<std::pair<int, int>> min_shooting_buildings(std::vector<int> H){
    n = sz(H);
    for (ll i = 1;i <= n;i ++)a[i] = H[i-1];
	solve();
	return ans;
}