#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(!newif(!node){
        printf("Memory allocation failed\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(search(root,key))
        printf("Found");
        else
        printf("Not found");
        return 0;
    }