#include<stdio.h>
#include<stdlib.h>
struct treenode{
    int data;
    struct treenode*left;
    struct treenode*right;
};
struct treenode*creatnode(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 creatnode(value);
    if(value<root->data)
    root->left=insert(root->left,value);
    else
    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;
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");
        return 0;
    }
    struct treenode*root=NULL;
    for(int i=0;i<n;i++){
        int value;
        scanf("%d",&value);
        root = insert(root,value);
    }
    int target
    scanf("%d",&target);
    if(search(root, target))
    printf("found");
    else
    printf("not found");
    return 0;
}