#include<stdio.h>
#include<stdlib.h>


typedef struct node
{
    char data;
    struct node* left,*right;
}Node;
Node *root=NULL;
Node *create(char num)
{
    Node *newNode = (Node*)malloc(1*sizeof(Node));
    newNode->data=num;
    newNode->left=NULL;
    newNode->right=NULL;
    return newNode;
}
Node* insert(Node* root,int num)
{
    if(root==NULL)
      return create(num);
     if(num<root->data)
       root->left=insert(root->left,num);
     else if(num>root->data)
       root->right=insert(root->right,num);
      return root;
}

void preOrder(Node* root)
{
    if(root!=NULL)
    {
        printf("%d ",root->data);
        preOrder(root->left);
        preOreder(root->right);
    }
}
void inOrder(Node* root)
{
    if(root != NULL)
    {
        inOrder(root->left);
        printf("%d ",root->data);
        inOrder(root->right);
    }
}
void postOrder(Node* root)
{
    if(root!=NULL)
    {
        postOrder(root->left);
        postOrder(root->right);
        printf("%d ",root->data);
    }
}
int main()
{
    int n,i,num;
    scanf("%d",&n);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&num);
        root=insert(root,num);
    }
    preOrder(root);
    return;
}