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

typedef struct TreeNode{
    int data;
    struct TreeNode *left;
    struct TreeNode *right;
}Node;

Node *root = NULL;

Node *create(int num){
    Node* newnode=(Node*)malloc(sizeof(Node));
    
    newnode->data=num;
    newnode->left = newnode->right = NULL;
    
    return newnode;
}

Node *insertBST(Node *root, int num){
    if(root==NULL){
        return create(num);
    }
    
    if(num<root->data){
        root->left=insertBST(root->left, num);
    }
    else{
        root->right=insertBST(root->right, num);
    }
    return root;
}

void postorder(Node *root){
    if(root==NULL){
        return;
    }
    inorder(root->left);
    inorder(root->right);
    printf("%d ", root->data);
}


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