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

typedef struct node{
    int data;
    struct node*right,*left;
}Node;
Node *root=NULL;
Node *create node(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 postOrder(Node*root){
    if(root!=NULL)
    postOrder(root->left);
    postOrder(root->right);
    printf("%d",root->data);
    
}
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);
        insert(root,num);
    }
    postOrder();
    return 0;
}