eh

#include <algorithm>
#include <cstdio>
using namespace std;
int n;
struct node{
	int data;
	struct node *nxt;
	struct node *pre;
}*head,*head1;
void creatlist(){
	head = (struct node*)malloc(sizeof(struct node));
	head -> data = 0,head -> nxt = NULL;
	struct node *tmphead = head;
	for (int i = 1;i <= n;i++){
		int x;
		scanf ("%d",&x);
		struct node *curtr = (struct node*)malloc(sizeof(struct node));
		curtr -> data = x,curtr -> nxt = NULL;
		tmphead -> nxt = curtr;
		tmphead = curtr;
	} 
}
void reverse(){
	head1 = (struct node*)malloc(sizeof(struct node));
	struct node *tmphead = head -> nxt;
	tmphead -> pre = NULL;
	while (tmphead -> nxt != NULL){
		struct node *curtr = tmphead -> nxt;
		curtr -> pre = tmphead;
		tmphead = tmphead -> nxt;
	}
	head1 -> pre = tmphead;
}
int main(){
	scanf ("%d",&n);
	creatlist();
	struct node *tmphead = head -> nxt;
	while (tmphead != NULL){
		printf("%d ",tmphead -> data);
		tmphead = tmphead -> nxt;
	}
	printf("\n");
	reverse();
	tmphead = head1 -> pre;
	while (tmphead != NULL){
		printf("%d ",tmphead -> data);
		tmphead = tmphead -> pre;
	}
}```