#include <bits/stdc++.h>
#define int long long
#define endl '\n'
using namespace std;

const int N = 1e6 + 10;
int head, e[N], ne[N], idx;
void init()
{
    head = -1;
    idx = 0;
}
void add_to_head(int x)
{
    e[idx] = x;
    ne[idx] = head;
    head = idx++;
}
void add(int k, int x)
{
    e[idx] = x;
    ne[idx] = ne[k];
    ne[k] = idx++;
}
void remove(int k)
{
    ne[k] = ne[ne[k]];
}
signed main()
{
    cin.tie(0)->ios::sync_with_stdio(0);

    int m;
    cin >> m;
    init();
    while (m--)
    {
        char op;
        cin >> op;
        if (op == 'H')
        {
            int x;
            cin >> x;
            add_to_head(x);
        }
        else if (op == 'D')
        {
            int k;
            cin >> k;
            k--;
            if (k == -1)
                head = ne[head];
            else
                remove(k);
        }
        else if (op == 'I')
        {
            int k, x;
            cin >> k >> x;
            add(--k, x);
        }
    }
    for (int i = head; i != -1; i = ne[i])
    {
        cout << e[i] << ' ';
    }
}