#include <stdio.h>
#include <stdlib.h>
typedef struct Node{
    int data;
    struct Node*left;
    struct Node*right;
}Node;
Node* createNode(int data){
    Node* newNode=(Node*)malloc(sizeof(Node));
    newNode->data=data;
    newNode->left=newNode->right=NULL;
    return newNode;
}
Node*insert(Node*root,int data){
    if(root==NULL){
        return createNode(data);
    }
    if(data<root->data){
        root->left=insert(root->left,data);
    }else{
        root->left=insert(root->right,data);
    }
    return root;
}
int search(Node*root,int target){
    if(root==NULL){
        return 0;
    }
    if(root->data==target){
        return 1;
    }
    if(target<root->data){
        return search(root->left,target);
    }else{
        return search(root->right,target);
    }
}
int main(){
    int n;
    scanf("%d",&n);
    if(n<=0){
        printf("invalid input\n");
        return 0;
    }
    Node*root=NULL;
    for(int i=0;i<n;i++){
        int val;
        scanf("%d",&val);
        root=insert(root,val);
    }
    int target;
    scanf("%d",&target);
    if(search(root,target)){
        print("found\n");
    }else{
        print("not found\n"),
    }
    return 0;
}