#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
    }
    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;
}