// editor1
#include<stdio.h>
#include<stdlib.h>
int size;

typedef struct node{
    int data;
    struct node *left,*right;
}Node;
Node *root=NULL;

Node1 *q;
int front=0,reat=-1;

void enQueue(Node *root){
    q->arr[++Node]=root;
}
Node* deQueue(){
    return q->arr[front++];
}

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);
    }else if(num < root->data){
        root->left=insert(root->left,num);
    }else if(num > root->data){
        root->right=insert(root->right,num);
    }return root;
}
void order(Node *root){
    q =(Node1*)malloc (sizeof(Node1));
    enQueue(root);
    while(front <= rear){
        Node *temp =deQueue();
        printf("%d ",temp->data);
        if(temp->left != NULL){
            enQueue(temp->left);
        }if(temp->right!= NULL){
            enQueue(temp->right);
        }
    }
    
}
int main(){
    int i,num;
    scanf("%d",&size);
    if(size<=0){
        printf("Invalid input");
        return 0;
    }
    for(i=0;i<size;i++){
        scanf("%d",&num);
        root=insert(root,num);
    }
    order(root);
    return 0;
}