#include<stdio.h>
#include<stdlib.h>
typedef struct node {
    int data;
    struct node*left,*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);
       root->left=insert(root->left,num);
    elseif(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;i++){
         scanf("%d",&num);
        if(num<0){
            printf("Invalid input");
            return 0;
        }
        root=insert(root,num);
    }
    inorder(root);
    return 0;
}