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

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

struct Node*createNode(int data){
    struct Node*newNode=(struct Node*)malloc(sizeof(structNode));
    if (!newNode){
        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 createNode(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 target){
    if (root==NULL)
        return 0;
    if (root->data==target)
        return 1;
    else if (target<root->data)
        return search(root->left,target);
    else 
        return search(root->right,target);
}

int main (){
    int n,value,target;
    scanf("%d",&n);
    
    if(n<=0){
        printf("Invalid input\n");
        return 0;
    }
    struct Node*root=NULL;
    for(int i =0;i<n;i++){
        scanf("%d",&value);
        root=insert(root,value);
    }
    scanf("%d",&target);
    if (target<0){
        printf(" Invalid input\n");
        return 0;
    }
    if (search(root,target))
        printf ("Found\n");
    else 
        printf("Not found\n");
    return 0;
        
}