// editor5
#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    int data;
    struct node *left,*right;
}node;
 node *root=NULL;
 
node *create(char 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 postorder(node *root)
{
    if(root!=NULL)
    postorder(root->left);
    postorder(root->right);
    printf("%d",root->data);
}
}

int main()
{
    int size;
    int num;
    scanf("%d",&size);
    if(size<0)
    {
        printf("Invalid input");
        return 0;
    }
    for(int i=0;i<size;i++)
    {
        scanf("%d",&num);
        root=insert(root,num);
    }
    postorder(root);
    return 0;
}