#include<iostream>  
using namespace std;  
struct node {  
    int data;  
    node *next;  
};  
node *head, *p, *r, *s, *t;  
int n, x, y;   
bool cz(int x, node*& prev) {  
    prev = NULL;  
    t = head;  
    while (t != NULL && t->data != x) {  
        prev = t;  
        t = t->next;  
    }  
    return t != NULL;  
}  
  
int main() {  
    head = new node;  
    head->next = NULL; 
    r = head;  
    cin >> n;   
    p = new node;  
    p->data = 1;  
    p->next = NULL;  
    head->next = p;  
  
    for (int i = 1; i <= n; i++) {  
        cin >> x;  
        if (x == 1) {  
            cin >> x >> y;  
            node* prev = NULL;  
            if (cz(x, prev)) {  
                s = new node;  
                s->data = y;  
                s->next = prev->next->next; 
                prev->next->next = s;  
            }  
        } else if (x == 2) {  
            cin >> x;  
            node* prev = NULL;  
            if (cz(x, prev) && prev->next->next != NULL) {  
                cout << prev->next->next->data << endl;  
            } else {  
                cout << 0 << endl;  
            }  
        } else if (x == 3) {  
            cin >> x;  
            node* prev = NULL;  
            if (cz(x, prev) && prev->next->next != NULL) {  
                node* toDelete = prev->next->next;  
                prev->next->next = toDelete->next;  
                delete toDelete; 
            }  
        }  
    }  
    return 0;  
}