#include<stdio.h>
#include<stdlib.h>
 typedef struct node{
     int data;
     struct node *left,*right;
 }Node;
 Node *root=NULL;
 Node* create(int 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 num;   
  }
  void preOrder(Node *root){
      if(root!=NULL){
          printf("%d",root->data);
          preOrder(root->left);
          preOrder(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 size,itr,num;
      scanf("%d",&size);
      for(itr=1;itr<=size;itr++){
          scanf("%d",&num);
          root=insert(root,num);
      }
      preorder(root);
  }