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


typedef struct node{
    int data;
    struct node *left;
    struct node *right;
}Node;

Node *root = NULL;

Node* create(int num){
    Node *newNode = (Node*)malloc(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){
        insert(root->left);
    }
    else if(num > root->data){
        insert(root->right);
    }
    return root;
}

void  preOrder(Node* root){
    if(root!=NULL){
        printf("%d ",root->data);
        preOrder(root->left);
        preOrder(root->right);
    }
}

int main(){
    int n,num;
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        scanf("%d",&num);
        insert(root,num);
    }
    preOrder(root);
}