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