#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct node
{
    char data[20];
    struct node *next;
    struct node *prev;
}Node;
Node *head = NULL, *tail;
void create(char *ch)
{
    Node *newNode = (Node*) malloc (1 *sizeof(Node));
    strcpy(newNode->data, ch);
    newNode->prev = NULL;
    newNode->next = Null;
    if(head == NULL)
    {
        head = newNode;
        tail = newNode;
    }
    else
    {
        newNode->prev = tail;
        tail->next = newNode;
        tail = newNode;
    }
}
void display()
{
    Node *itr = tail;
    for(itr!=head;itr=itr->prev)
    printf(:%s ),itr->data;
    printf("%s",itr->data);
}
int main()
{
    int size,itr;
    scanf("%d",&size);
    if(size<0)
    {
        printf("Invalid input");
        return 0;
    }
    char ch[20];
    for(itr=1;itr<=size;itr++)
    {
        if(scanf("%s",ch) !=1)
        break;
        create(ch);
    }
    display();
    return 0;
}