#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
    char data;
    struct node *left, *right;
}Node;
Node *root=NULL;
Node* create(char num)
{
    Node *newNode=(Node*) malloc (1 * sizeof(Node));
    newNode->data=num;
    newNode->left=NULL;
    newNode->right=NULL;
    return newNode;
}
Node* insert(Node *root,char 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;
}
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 size,num,itr;
    scanf("%d",&size);
    for(itr=1;itr<=size;itr++){
        scanf("%d",&num);
        root=insert(root,num);
    }
    Node *ans = serach(root,-20);
    if(ans!=NULL){
        printf("Found");
    else{
        printf("Not");
    return 0;
}