#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include<bits/stdc++.h>
#define pb push_back
#define be(a) a.begin(), a.end()
#define rbe(a) a.rbegin(), a.rend()
#define L(x, n) for (int x = 0; x < n; ++x)
#define cin(a) for (auto &i : a) cin >> i
#define cout(a, x) for (auto &i : a) cout << i << x; cout << '\n'
#define F first
#define S second
#pragma GCC optimize("Ofast")
using namespace std;
using namespace __gnu_pbds;
typedef pair <int, int> pii;
typedef unsigned int ui;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
template <class T> using oset = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
template <class T> using pqueue = priority_queue <T, vector <T>, greater <T>>;
//I love my wife - Elizaveta Minchakova

struct node {
    vector <int> history, learned;
    int parentH = -1, H = -1, parentL = -1, L = -1;
} r;

int pos[500001];

int main() {
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n, m;
    cin >> n >> m;
    int cnt = 0;
    pos[++cnt] = 0;
    vector <node> a = {r};
    while (n--) {
        string op;
        int c, p;
        cin >> op >> c;
        int oldC = c;
        c = pos[c];
        if (op[0] == 'l') {
            cin >> p;
            a[c].learned.push_back(p);
            a[c].history = {};
            a[c].parentH = a[c].H = -1;
        } else if (op[0] == 'c') {
            if (op[1] == 'h') {
                if (a[c].learned.size()) {
                    cout << a[c].learned.back() << '\n';
                } else if (a[c].parentL != -1) {
                    cout << a[a[c].parentL].learned[a[c].L] << '\n';
                } else {
                    cout << "basic\n";
                }
            } else {
                if (a[c].history.size()) {
                    r.parentH = c;
                    r.H = a[c].history.size() - 1;
                } else {
                    r.parentH = a[c].parentH;
                    r.H = a[c].H;
                }
                if (a[c].learned.size()) {
                    r.parentL = c;
                    r.L = a[c].learned.size() - 1;
                } else {
                    r.parentL = a[c].parentL;
                    r.L = a[c].L;
                }
                pos[oldC] = a.size();
                a.pb(r);
                pos[++cnt] = a.size();
                a.pb(r);
            }
        } else if (op[1] == 'e') {
            if (a[c].history.size()) {
                a[c].learned.push_back(a[c].history.back());
                a[c].history.pop_back();
            } else {
                a[c].learned.push_back(a[a[c].parentH].history[a[c].H--]);
                if (a[c].H == -1) {
                    a[c].parentH = a[a[c].parentH].parentH;
                    if (a[c].parentH != -1) {
                        a[c].H = a[a[c].parentH].history.size() - 1;
                    }
                }
            }
        } else {
            if (a[c].learned.size()) {
                a[c].history.push_back(a[c].learned.back());
                a[c].learned.pop_back();
            } else {
                a[c].history.push_back(a[a[c].parentL].learned[a[c].L--]);
                if (a[c].L == -1) {
                    a[c].parentL = a[a[c].parentL].parentL;
                    if (a[c].parentL != -1) {
                        a[c].L = a[a[c].parentL].learned.size() - 1;
                    }
                }
            }
        }
        //cout << endl;
        /*for (int i = 1; i <= cnt; ++i) {
            cout << i << ": " << pos[i] << '\n';
        }
        for (auto &i : a) {
            cout << "learned: ";
            cout(i.learned, ' ');
            cout << "history: ";
            cout(i.history, ' ');
            cout << i.parentL << ' ' << i.L << '\n';
            cout << i.parentH << ' ' << i.H << '\n' << endl;
        }*/
    }

    return 0;
}