#include <iostream>

using namespace std;

struct Nod
{
    int info;
    Nod *st, *dr;
};
Nod *L, *U;

void Creare (int x)
{
    L = new Nod;
    U = L;
    L -> st = L -> dr = NULL;
    l -> info = x;
}

void InsInainte (Nod *p, int x)
{
    Nod *q = new Nod;
    q -> info = x;
    q -> dr = p;
    q -> st = p -> st;
    p -> st -> dr = q;
    p -> st = q;
}

void InsInceput (int x)
{
    Nod *p = new Nod;
    p -> info = x;
    p -> dr = L;
    p -> st = NULL;
    L -> st = p;
    L = p;
}

void ParcSD ()
{
    for (Nod *p = L; p != NULL; p = p -> dr)
        cout << p -> info << " ";
    cout << "\n";
}

int main()
{
    int n;
    cin >> n;
    cin >> x;
    Creare(x);
    for (i = 2; i <= n; i++)
        InsInainte()

    return 0;
}