#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));
    newnode->data= data;
    newnode->left= newnode->right = NULL;
    return newnode;
}
struct node* insert(struct node* root, int x){
    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(key > root->data){
            return search(root->right, key);
        }
        if(key< root->data)
        return search(root->left, key);
    }
    return 1;
    
}
int main(){
    int n, target;
    scanf("%d",&value);
    if(n <0){
        printf("Invalid input");
        return 0;
    }
    struct node* root=NULL;
    for(int i=0; i<n; i++){
        int value;
        scanf("%d",&value);
        root = insert(root,value);
    }
    scanf("%d", &target);
    if(search(root,target)){
        printf"Found");
    }
    else{
        printf("not found");
}
return 0;
}