// editor5
#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(node==NULL)
    {
        return create(num);
    }
    else if(num<root->data)
    {
        root->left=insert(root->left,num);
        
    }
    else if(num>root->data)
    {
        root->right= inser(root->right,num);
    }
    return root;
}
void postorder(node *root)
{
    if(root!=NULL)
    {
        postorder(left->root);
        postorder(right->root);
        printf("%d",root->data);
    }
}
int main()
{
    int size,num;
    scanf("%d",&size);
    for(i=0;i<size;i++)
    {
        scanf("%d",&num);
    }
    postorder(root);
    return 0;
}