#include <iostream>
#include <iomanip>
using namespace std;

struct Node
{
    double key;
    struct Node *left;
    struct Node *right;
    int height;
};

int max(int a, int b);

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(double key)
{
    struct Node* node = new Node;
    node->key = key;
    node->left = NULL;
    node->right = NULL;
    node->height = 1;
    return(node);
}

struct Node *rightRotate(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(x->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);
}
bool containsRecursive(Node *current, double key)
{
    if (current == NULL)
    {
        return false;
    }

    if (current->key == key)
    {
        return true;
    }

    if (key < current->key)
    {
        return containsRecursive(current->left, key);
    }
    else
    {
        return containsRecursive(current->right, key);
    }
}
bool contains(Node* root, double key)
{
    if (root == NULL)
    {
        return false;
    }

    return containsRecursive(root, key);
}
Node* add(Node* node, double key)
{
    if (node == NULL)
        return newNode(key);

    if (key < node->key)
        node->left = add(node->left, key);
    else if (key > node->key)
        node->right = add(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;
}

Node * minkeyNode(Node* node)
{
    Node* current = node;
    while (current->left != NULL)
        current = current->left;

    return current;
}

Node* remove(Node* root, double key)
{
    if (root == NULL)
        return root;

    if ( key < root->key )
        root->left = remove(root->left, key);


    else if( key > root->key )
        root->right = remove(root->right, key);

    else
    {
        if( (root->left == NULL) || (root->right == NULL) )
        {
             Node *temp = root->left ? root->left :
                                    root->right;
            if (temp == NULL)
            {
                temp = root;
                root = NULL;
            }
            else
                *root = *temp;
            free(temp);
        }
        else
        {
             Node* temp = minkeyNode(root->right);

            root->key = temp->key;

            root->right = remove(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 leftRotate(root);

    if (balance < -1 && getBalance(root->right) > 0)
    {
        root->right = rightRotate(root->right);
        return leftRotate(root);
    }

    return root;
}
void printRecursive(Node *current)
{
    if (current == NULL)
    {
        return;
    }

    printRecursive(current->left);
    cout << fixed << setprecision(6) << current->key * 1.0 << " ";
    printRecursive(current->right);
}

int main()
{
    Node* root = NULL;
    string operation;
    double number;
    int N;

    cin >> N;
    cout << fixed;

    for (size_t i = 0; i < N; i++)
    {
        cin >> operation;
        if (operation != "print")
        {
            cin >> number;
        }

        if (operation == "add")
        {
            if(contains(root,number)) cout << number << " already added\n";
            else root = add(root, number);
        }
        else if (operation == "remove")
        {
            if(!contains(root,number)) cout << number << " not found to remove\n";
            else root = remove(root, number);
        }
        else if (operation == "contains")
        {
            if (contains(root, number))
            {
                cout << "yes" << endl;
            }
            else
            {
                cout << "no" << endl;
            }
        }
        else if (operation == "print")
        {
            printRecursive(root);
        }
    }

    return 0;
}