#include<stdio.h>
#include<stdlib.h>
struct Node{
    int data;
    struct node*left
    struct node*right;
};
struct node*create(int data){
    struct node*newnode=(struct node*)malloc(sizeof(struct node));
    if(!newnode){
    printf("Memory allocation faild\n");
    exit(1);
}
   newnode->data=data;
   newnode->left=newnode->right=NULL;
   return newnode;
}
struct node* insert(struct node*root,int data){
    if(root==NULL)
    
        return create(data);
    
    if(data<root->data)
    
       root->left=insert(root->left,data);
     else if(data>root->data)
       root->right=insert(root->right,data);
       return root;
    
}
int search(struct node*root,int key)
{
    if(root==NULL)
        return 0;
    if(root->data==key)
     return 1;
     else if(key<root->data)
     return search(root->left,key);
     else
     return search(root->right,key);
}
int main()
{
    int n,value,key;
    scanf("%d",&n);
    if(n<=0)
    {
        printf("Invalid input");
        return 0;
    }
    struct node*root=NULL;
    for(int i =0;i<n;i++){
        scanf("%d",&value);
        root=insert(root,value);
    }
    scanf("%d",&key);
    if(serch(root,key))
    printf("Found");
    else
    printf("Not found");
    return 0;
    
}