#include <stdio.h>
#include <stdlib.h>
typedef struct Node{
    int data;
    struct Node *left, *right;
}node;

node *root = NULL;

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

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

void preorder(node *root){
    if(root!=NULL){
        if(root->left==NULL && root->right==NULL)
            printf("%d ",root->data);
        inorder(root->left);
        inorder(root->right);
    }
}

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