#include<stdio.h>
#include<stdlib.h>
typedef struct TreeNode{
    int data;
    struct TreeNode *left;
    struct TreeNode *right;
    
}node;
node *root=NULL;
node *create (int v){
    node *newnode=(node*)malloc(sizeof(node));
    newnode->data=v;
    newnode->left=newnode->right=NULL;
    return newnode;
}
node* insert(node *root,int v){
    if(root==NULL)
    return create(v);
    if(v<root->data)
    root->left=insert(root->left,v);
    else
    root->right=insert(root->right,v);
    return root;
}
void search(node* root,int v){
    if(root==NULL)
    return 0;
if(root->data==v)
return 1;
if(v<root->data)
return search(root->left,v);
else
return search(root->right,v);
return 0;}
int main(){
    int n;
    scanf("%d",&n);
    if(n<=0){
        printf("Invalid input");
    }
    
    int x;
    for(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");
}