#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    int data;
    struct node*left,*right;
}a;
a*root;
a*create(int num){
    a*newnode=(a*)malloc(1*sizeof(a));
    newnode->right=NULL;
    newnode->data=num;
    newnode->left=NULL;
    return newnode;
}
a* insert(a*root,int num){
    if(root==NULL)
        return create(num);
    if(num<root->data)
        root->left=insert(root->left,num);
    else if(num>root->data)
        root->right=insert(root->right,num);
 
}
a*search(a*root,int num){
    if(root==NULL||root->left,num)
        return root;
    if(num<root->data)
        return search(root->left,num);
    if(num>root->data){
        return search(root->right,num);
    }
    
}
int main(){
    int size,num,val,i;
    if(size<0)
        printf("Invalid input");
        return 0;
    for(i=0;i<size;i++){
        scanf("%d",&num);
        root=insert(root,num);
    }
    scanf("%d",&val);
    a*search(root,val);
    if(val!==NULL){
        printf("Found");
    }
    else{
        printf("Not found");
    }