#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 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;
    idx++;
}
void add(int k, int x) {
    e[idx] = x;
    ne[idx] = ne[k];
    ne[k] = idx;
    idx++;
}
void remove(int k) {
    ne[k] = ne[ne[k]];
}
int main()
{
    int m;
    cin >> m;
    init();
    while (m--) {
        char c;
        int k, x;
        cin >> c;
        if (c == 'H') {
            cin >> x;
            add_to_head(x);
        }
        else if (c == 'D') {
            cin >> k;
            if (k == 0)
                head = ne[head];
            else remove(k - 1);
        }
        else if (c == 'I') {
            cin >> k >> x;
            add(k - 1, x);
        }
    }
    for (int i = head; i != -1; i = ne[i]) {
        cout << e[i] << ' ';
    }
    cout << endl;
    return 0;
}