#include<stdio.h>
#include<stdlib.h>

struct treeNode
{
    int data;
    struct TreeNode *left;
    struct TreeNode *right;
};

struct TreeNode *createNode(int value)
{
    struct TreeNode *newNode=(struct node*)malloc(sizeof(struct TreeNode));
    newNode->data=value;
    newNode->left=NULL;
    newNode->right=NULL;
    return newNode;
}
struct TreeNode *insert(struct TreeNode *root,int val)
{
    if(root==NULL)
       return createNode(val);
    if(val<root->data)
       root->left=insert(root->left,val);
    else if(val>root->data)
       root->right=insert(root->right,val);
    return root;
}
struct TreeNode *search(struct TreeNode *root, int val)
{
    if(root==NULl||root->data==val)
       return root;
    if(val<root->data)
       return search(root->left,val);
    return search(root->right,val);
}
int main()
{
    int i,target,n;
    scanf("%d",&n);
    if(n<=0)
    {
        printf("invalid input");
        return 0;
    }
    struct TreeNode *root=NULL;
    for(i=0;i<n;i++)
    {
        int val;
        scanf("%d",&val);
        root=insert(root,val);
    }
    scanf("%d",&target);
    if(search(root,target))
      printf("found");
    else
      printf("not found");
    return 0;
}