#include <bits/stdc++.h>

using namespace std;
using ll = long long;

constexpr ll mod = 998244353;

template<ll mod>
struct Mint {
  using M=Mint; ll v;
  M& put(ll x) { v=(x<mod)?x:x-mod; return *this; }
  Mint(ll x=0) { put(x%mod+mod); }
  M operator+(M m) {return M().put(v+m.v);}
  M operator-(M m) {return M().put(v+mod-m.v);}
  M operator*(M m) {return M().put(v*m.v%mod);}
  M operator/(M m) {return M().put(v*m.inv().v%mod);}
// BEGIN IGNORE
  M operator+=(M m) { return put(v+m.v); }
  M operator-=(M m) { return put(v+mod-m.v); }
  M operator*=(M m) { return put(v*m.v%mod); }
  M operator/=(M m) { return put(v*m.inv().v%mod); }
// END IGNORE
  bool operator==(M m) { return v==m.v; }
  M pow(ll m) const {
    M x=v, res=1;
    while (m) {
      if (m&1) res=res*x;
      x=x*x; m>>=1;
    }
    return res;
  }
  M inv() { return pow(mod-2); }
};

using mint = Mint<mod>;

#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp> // for tree
#include<ext/pb_ds/tag_and_trait.hpp> // for tree

using namespace __gnu_pbds;

template <typename T>
using gtree = tree<T, null_type, less<T>, rb_tree_tag,
  tree_order_statistics_node_update>;

int main(){

  cin.tie(0);
  cin.sync_with_stdio(0);

  int n;
  cin >> n;
  vector<int> p(n);
  for(int i = 0; i < n; ++i){
    cin >> p[i];
    --p[i];
  }
  vector<int> inv(n);
  for(int i = 0; i < n; ++i){
    inv[p[i]] = i;
  }
  gtree<int> gt;
  for(int i = 0; i < n; ++i){
    gt.insert(i);
  }
  int k = 0;
  vector<int> q;
  for(int iter = 0; iter < n / 2; ++iter){
    while(true){
      int key = inv[k];
      if(gt.find(key) != gt.end() && gt.order_of_key(key) != gt.size() - 1){
        int idx1 = key;
        int idx2 = *gt.find_by_order(gt.order_of_key(key) + 1);
        gt.erase(idx1);
        gt.erase(idx2);
        q.emplace_back(p[idx1]);
        q.emplace_back(p[idx2]);
        break;
      }
      ++k;
    }
  }
  for(int i = 0; i < q.size(); ++i){
    cout << q[i] + 1 << " \n"[i + 1 == q.size()];
  }
}