#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));
    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)
        root->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->right, target);
}

int main() {
    int n;
    scanf("%d", &n);
    if (n <= 0 || n < -10 || n > 10) {
        printf("Invalid input\n");
        return 0;
    }
    int *values = {0, -5, 5, -10, -3, 3, 7, -7, 10, -1};
    int size = sizeof(values) / sizeof(values[0]);

    struct Node* root = NULL;
    for (int i = 0; i < size; i++) {
        root = insert(root, values[i]);
    }
    if (search(root, n))
        printf("Found\n");
    else
        printf("Not found\n");

    return 0;
}