#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 newnode create(value);
    if(root>root->data)
    root->left=insert(root->left,value);
    else
    root->right=insert(root->right,value);
    return root;
    
}
intsearch(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("Invaild Input");
        return 0;
        
    }
}
struct Treenode*root=NULL;
for(inti=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;
    }
}
}