#include <stdio.h>

struct Node{
    int prev, next;
};

Node map[100000];

int main() {
    map[0].prev = 1;
    map[0].next = 1;
    map[1].prev = 0;
    map[1].next = 0;
    int n;
    int cmd, x, y;
    scanf("%d", &n);
    while (n) {
        scanf("%d %d", &cmd, &x);
        switch(cmd) {
            case 1: {
                scanf("%d", &y);
                map[y].prev = x;
                map[y].next = map[x].next;
                map[x].next = y;
                map[map[y].next].prev = y;
                break;
            }
            case 2: {
                printf("%d\n", map[x].next);
                break;
            }
            case 3: {
                map[map[x].prev].next = map[x].next;
                map[map[x].next].prev = map[x].prev;
                break;
            }
        }
        n--;
    }

    int cur = map[0].next;
    while (cur != 0) {
        printf("%d\n", cur);
        cur = map[cur].next;
    }
    return 0;
}