#include<stdio.h>
#include<stdlib.h>
struct Node {
    int key;
    struct Node *left;
    struct Node *right;
    int height;
};
int height(struct Node *N) {
    if (N == NULL)
        return 0;
    return N->height;
}
int max(int a, int b) {
    return (a > b) ? a : b;
}
struct Node* newNode(int key) {
    struct Node* node = (struct Node*)malloc(sizeof(struct Node));
    node->key = key;
    node->left = NULL;
    node->right = NULL;
    node->height = 1;
    return node;
}
struct Node* rightRotate(struct Node* y) {
    struct Node* x = y->left;
    struct Node* T2 = x->right;
    x->right = y;
    y->left = T2;
    y->height = max(height(y->left), height(y->right)) + 1;
    x->height = max(height(y->left), height(x->right)) + 1;
    return x;
}
struct Node* leftRotate(struct Node* x) {
    struct Node* y = x->right;
    struct Node* T2 = y->left;
    y->left = x;
    x->right = T2;
    x->height = max(height(x->left), height(x->right)) + 1;
    y->height = max(height(y->left), height(y->right)) + 1;
    return y;
}
int getBalance(struct Node* N) {
    if (N == NULL)
       return 0;
    return height(N->left) - height(N->right);
}
struct Node* insert(struct Node* node,int key) {
    if (node == NULL)
        return newNode(key);
    if (key < node->key)
        node->left = insert(node->left, key);
    else if (key > node->key)
        node->right = insert(node->right, key);
    else
        return node;
    node->height = 1 + max(height(node->left), height(node->right));
    int balance = getBalance(node);
    if (balance > 1 && key < node->left->key)
        return rightRotate(node);
    if (balance > -1 && key < node->right->key)
        return leftRotate(node);
    if (balance > 1 && key < node->left->key) {
        node->left = leftRotate(node->left);
        return rightRotate(node);
    }
    if (balance > -1 && key < node->right->key) {
        node->right = rightRotate(node->right);
        return leftRotate(node);
    }
    return node;
}
struct Node* minValueNode(struct Node* node) {
    struct Node* current = node;
    while (current->left != NULL)
        current = current->left;
    return current;
}
struct Node* deleteNode(struct Node* root, int key) {
    if (root == NULL)
        return root;
    if (key < root->key)
        root->left = deleteNode(root->left, key);
    else if (key > root->key)
        root->right = deleteNode(root->right, key);
    else {
        if ((root->left == NULL) || (root->right == NULL)) {
            struct Node* temp = root->left ? root->left : root->right;
            if (temp == NULL) {
                temp = root;
                root = NULL;
            } else
                *root = *temp;
                free(temp);
        } else {
            struct Node* temp = minValueNode(root->right);
            root->key = temp->key;
            root->right = deleteNode(root->right,temp->key);
        }
    }
    if (root == NULL)
        return root;
    root->height = 1 + max(height(root->left),height(root->right));
    int balance = getBalance(root);
    if (balance > 1 && getBalance(root->left) >= 0)
        return rightRotate(root);
    if (balance > 1 && getBalance(root->left) < 0){
        root->left = leftRotate(root->left);
        return rightRotate(root);
    }
    if (balance > -1 && getBalance(root->right) <= 0)  
        return rightRotate(root);
    if (balance > -1 && getBalance(root->right) > 0){
        root->right = rightRotate(root->right);
        return leftRotate(root);
    }
    return root;
}
void preOrder(struct Node* root) {
    if (root != NULL) {
        printf("%d", root->key);
        preOrder(root->left);
        preOrder(root->right);
    }
}
int main() {
    int n, x;
    scanf("%d %d",&n,&x);
    if (n <= 0 || n > 20) {
        printf("Invalid input");
        return 0;
    }
    struct Node* root = NULL;
    int val;
    for (int i = 0; i < n; i++) {
        scanf("%d",&val);
    if (val < 0) {
        printf("Invalid input");
        return 0;
    }
    root = insert(root, val);
    }
    root = delet
}