#include <iostream>
#include <cstdio>
using namespace std;
const int N = 1e5 + 5;

int cnt, head = -1;
struct Edge{
    int data;
    int next;
}edge[N];

int main()
{
    int n;
    scanf("%d", &n);

    while (n--)
    {
        char op;
        cin >> op;
        int k, x;
        if (op == 'H')
        {
            scanf("%d", &x);
            edge[++cnt] = {x, head};
            head = cnt;
        }
        else if (op == 'D')
        {
            scanf("%d", &k);
            if (!k) 
                head = edge[head].next;
            else
                edge[k].next = edge[edge[k].next].next;
        }
        else 
        {
            scanf("%d %d", &k, &x);
            edge[++cnt] = {x, edge[k].next};
            edge[k].next = cnt;
        } 
    }

    for (int i = head; i != -1; i = edge[i].next)
        printf("%d ", edge[i].data);
    return 0;
}