#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(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);
     }
     
 }
 int main(){
     int size,itr,num;
     scanf("%d",&size);
     for(itr=1;itr<size;itr++){
         scanf("%d",&num);
         root=insert(root,num);
 }