#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    int data;
    struct node *left;
    struct node *right;
}Node;
Node* root=NULL;
Node* create(int val){
    if(val==0){
        return NULL;
    }
    Node* newnode=(Node*)malloc(sizeof(Node));
    newnode->data=val;
    newnode->left=newnode->right=NULL;
    return newnode;
    Node* insertBST(Node *root,int t){
        if(root==NULL)
        return create(t);
        if(val<root->data){
            root->left=insertBST( root->left, t);
        }
        else
        root->right=insertBST( root->right, t);
        return root;
    }
}
int main(){
    int size;
    scanf("%d",&size);
    if(size<=0){
        printf("Invalid input");
        return 0;
    }
    Node *root=NULL;
    for(int i=0; i<size; i++){
        int time;
        scanf("%d",&time);
    }
    root= insertBST(root,time);
    postorder(root);
}