#include <iostream>

using namespace std;


char c;
int idx = 0, head = -1;
const int N = 100010;
int ne[N], e[N];

void add_h(int x)
{
    e[idx] = x;
    ne[idx] = head;
    head = idx++;
}

void add_k(int k, int x)
{
    e[idx] = x;
    ne[idx] = ne[k];
    ne[k] = idx++;
}

void dele(int k)
{
    ne[k] = ne[ne[k]];
}

int main()
{
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> c;
        int k, x;
        switch(c)
        {
            case 'H' :
            {
                cin >> x;
                add_h(x);
                break;
            }
            case 'I' :
            {
                cin >> k >> x;
                add_k(k - 1, x);
                break;
            }
            case 'D' :
            {
                cin >> k;
                if (!k) head = ne[head];
                else dele(k - 1);
                break;
            }
        }
    }
    for (int i = head; i != -1; i = ne[i])
        cout << e[i] << ' ';
    return 0;
}