#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->right=NULL;
    newnode->left=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 if(num>root->data)
    {
        root->right=insert(root->right,num);
    }
    return root;
}
void inoder(Node *root)
{
    if(root!=NULL)
    {
        printf("%d",root->data);
        inorder(root->left);
        inorder(root->right);
    }
}
int main()
{
    int n,num;
    scanf("%d",&n);
    if(n==0||n<0)
    {
        printf("Invalid input");
        return 0;
    }
    for(i=1;i<=n;i++)
    {
        scanf("%d",&num);
        root=insert(root,num);
    }
    inoder(root);
}