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

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

Node *root=NULL;

Node *create(int num){
    // if(root==NULL){
    //     retun;
    // }
    Node *newnode=(Node*)malloc(sizeof(Node));
    
    newnode->data=num;
    newnode->left=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{
        root->right=insert(root->right, num);
    }
    
    return root;
    
}

void level(Node* root){
    if(root==NULL){
        return;
    }
    Node* queue[100];
    int front = 0, rear = 0;
    queue[rear++] = root;
    
    while(front < rear0){
        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 n, num;
    scanf("%d", &n);
    if(n<0){
        printf("Invalid input");
        rreturn 0;
    }
    for (int i=0; i<n; i++){
        scanf("%d", &num);
        
        root=insert(root,num);
    }
    level(root);
}