#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
    int data;
    struct node *right,*left;
} Node;
Node *create(int num)
{
    Node *newnode=(Node*)malloc(sizeof(Node));
    newnode->data=num;
    newnode->left=NULL;
    newnode->right=NULL;
    return newnode;
}
Node *insert(Node *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);
       return root;
     
}
void inorder(Node*root)
{
    if(root!=NULL)
    {
        printf("%d",root->data);
        inorder(root->left);
        inorder(root->right);
    }
}
Node *search(Node *root,int num)
{
    if(root==NULL||root->data==num)
      return root;
    if(num<root->data)
      return  search(root->left,num);
     return search(root->right,num);
}
int main()
{
    int n,i,num;
    if(scanf("%d",&n)<=0)
    {
        printf("Invalid input");
        return 0;
    }
    for(i=0;i<n;i++)
    {
        scanf("%d",&num);
        root=insert(root,num);
    }
    Node *ans=search(root,20)
    if(ans!=NULL)
    {
        printf("Found");
    }
    else
    {
        printf("Not Found");
    }
}