#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 TreeNode*)malloc(sizeof(struct TreeNode));
    newNode->data=value;
    newNode->left=newNode->right=NULL;
    return newNode;
}
struct TreeNode* insert(struct TreeNode*root,int value)
{
    if(root==NULL)
    return createNode(value);
    if(value<root->data)
    root->left=insert(root->left,value);
    else if(value>root->data)
    root->right=insert(root->right,value);
    return root;
}
int search(struct TreeNode* 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,target;
    scanf("%d",&n);
    
    if(n<=0){
        printf("Invalid Input");
        return 0;
    }
    struct TreeNode*root=NULL;
    for(int i=0;i<n;i++){
        int val;
        scanf("%d",&val);
        root=insert(root,val);
    }
    scanf("%d",&target);
    
    if(search(root,target))
    printf("found");
    else
    orintf("Not found");
    
    return 0;
}