#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->left,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;
}