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

typedef struct treeNode{
    int data;
    struct TreeNode *left;
    struct TreeNode *right;
    
}Node;

Node* create(int num){
    Node* newnode = (Node*)malloc(sizeof(Node*));
    newnode->data = num;
    newnode -> left = newnode->right = NULL;
    return newnode;
}

Node* insertBST(Node* root,int num){
    if(root==NULL){
        return create(num);
    }
    if(num<root->data){
        root->left = insertBST(root->left,num);
    }
    else{
        root->right = insertBST(root->right,num);
        
    }
    return root;
}

void levelorder(Node* root){
    if(root==NULL){
        return;
    }
    Node* queue[100];
    int front =0,rear=0;
    queue[rear++]=root;
    while(front<rear){
        Node* curr = queue[front++];
        printf("%d ",curr->data);
        if(curr->left){
            queue[rear++] = curr->left;
        }
        if(curr->right){
            queue[rear++] = curr->right;
        }
    }
    
    int main(){
        int size;
        Node* root = NULL;
        scanf("%d",&size);
        if(size<=0){
            printf("Invalid input");
            return 0;
        }
        int num;
        for(int i=0;i<size;i++){
            scanf("%d",&num);
            root = inserBST(root,num);
        }
        levelorder(root);
        return 0;
    }
    
    
    
    
    
    
    
    
    
}