#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(struct Node));
    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;    
}