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