#include<stdio.h>
#include<stdlib.h>
typedef struct treenode{
    int data;
    struct treenode *left;
    struct treenode *rigth;
}node;

node *root=NULL;
node *create (int num){
    node *newnode=(node*)malloc(sizeof(node));
    newnode->data=num;
    newnode->left=newnode->right=NULL;
    return newnode;
}
node* insertBST(node *root,int num){
    if(root==NULL)
    return craete(num);
    if(num<root->data)
    root->left=insertBST(root->left,num);
    else
    root->right=insertBST(root->right,num);
    return root;
}

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