#include <fstream>
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

ifstream in ("algsort.in");
ofstream out("algsort.out");

int n;
int v[500001];
vector<int> heap;

int father (int idx)
{
    if (idx == 0) return -1;
    
    return idx / 2;
}

int minim ()
{
    return heap[0];
}

void pop_heap()
{
    if (heap.size() <= 1)
        return;

    heap[0] = heap[heap.size() - 1];
    heap.pop_back();
    
    for (int i = 0; ;)
    {    
        if ( i * 2 + 2  > heap.size() - 1 )
            break;
    
        int fiu_stg = heap[i * 2 + 1];
        int fiu_dr  = heap[i * 2 + 2];
        
        
        if (heap[i] < fiu_stg && heap[i] < fiu_dr)
            break;
        
        if (fiu_stg < fiu_dr)
        {
            swap(heap[i], heap[i * 2 + 1]);
            
            i = i * 2 + 1;
        }
        else
        {
            swap(heap[i], heap[i * 2 + 2]);
            
            i = i * 2 + 2;
        }
    }
    
    /*
    for (int i = 0; i < heap.size(); ++i)
        cout << heap[i] << " ";
    cout << "\n";
    */
}

void push_heap (int val)
{
    heap.push_back(val);
    int poz = heap.size() - 1;
    for (int i = heap.size() - 1; i >= 0; i = father(i))
        if (val < heap[i])
        {
            int aux = heap[i];
            heap[i] = val;
            heap[poz] = aux;
            poz = i;
        }
    
    /*       
    for (int i = 0; i < heap.size(); ++i)
        cout << heap[i] << " ";
    cout << "\n";
    */
}

int main()
{
    in >> n;
    for (int i = 1; i <= n; ++i)
        in >> v[i];
        
    for (int i = 1; i <= n; ++i)
        push_heap (v[i]);
    

    for (int i = 1; i < n - 1; ++i)
    {
        out << minim() << " ";
        pop_heap();
    }
    
    if (heap[0] > heap[1])
        out << heap[1] << " " << heap[0];
    else
        out << heap[0] << " " << heap[1];
        
}