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

typedef struct node{
    int data;
    struct node*right,*left;
}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)
        root->left=insert(root->left,num);
    if(num > root->data)
        root->right=insert(root->right,num);
    return root;
}
void inOrder(Node*root){
    if(root!=NULL){
        inOrder(root->left);
        printf("%d ",root->data);
        inOrder(root->right);
    }
}
int main(){
    int size,i,num;
    scanf("%d",&size);
    if(size<=0){
        printf("Invalid input");
        return 0;
    }
    for(i=0;i<size+1;i++){
        if(!scanf("%d",&num) || num<0{
            printf("Invalid input");
            return 0;
        }
        root=insert(root,num);
    }
    inOrder(root);
    return 0;
}