#include<iostream>
#include<random>


using namespace std;

mt19937 rng(time(0));

struct Node
{
	int x, y;
	int tSize;
	Node* left;
	Node* right;

	Node(int x_)
	{
		x = x_;
		y = rng();
		tSize = 1;
		left = nullptr;
		right = nullptr;
	}

};


int tRecalc(Node* t)
{
	if (t == nullptr)
		return 0;
	t->tSize = 1;
	if (t->left)
		t->tSize += t->left->tSize;
	if (t->right)
		t->tSize += t->right->tSize;
	return t->tSize;
}

int GetSize(Node* t)
{
	if (t == nullptr)
		return 0;
	return t->tSize;
}


pair<Node*, Node*> Split(Node* t, int x)
{
	if (t == nullptr)
		return { nullptr, nullptr };

	if (x < t->x)
	{
		pair <Node*, Node*> leftres = Split(t->left, x);
		t->left = leftres.second;
		tRecalc(t);
		return { leftres.first, t };
	}
	else
	{
		pair <Node*, Node*> rightres = Split(t->right, x);
		t->right = rightres.first;
		tRecalc(t);
		return { t, rightres.second };
	}
}

Node* Merge(Node* l, Node* r)
{
	if (l == nullptr)
		return r;
	if (r == nullptr)
		return l;

	if (l->y >= r->y)
	{
		l->right = Merge(l->right, r);
		tRecalc(l);
		return l;
	}
	else
	{
		r->left = Merge(l, r->left);
		tRecalc(r);
		return r;
	}
}



Node* Insert(Node* t, int x)
{
	Node* newnode = new Node(x);
	//auto [L, R] = Split(t, x); 
	auto lr = Split(t, x);
	return Merge(Merge(lr.first, newnode), lr.second);
}


Node* Remove(Node* t, int x)
{
	auto lr = Split(t, x);
	auto temp = Split(lr.first, x - 1);
	//добавить освобождение памяти
	return Merge(temp.first, lr.second);
}


bool TreapFind(Node* t, int x)
{
	if (t == nullptr)
	{
		return 0;
	}
	if (x == t->x)
		return 1;
	if (x > t->x)
		return TreapFind(t->right, x);
	if (x < t->x)
		return TreapFind(t->left, x);
}


Node* kth(Node* t, int k)
{
	if (t == nullptr)
		return nullptr;
	if (GetSize(t->left) == k - 1)
		return t;
	if (GetSize(t->left) > k - 1)
		return kth(t->left, k);
	if (GetSize(t->left) == k - 1)
		return kth(t->left, k - GetSize(t->left) - 1);
}


void TreapOutput(Node* t, int depth)
{
	if (t == nullptr)
		return;
	TreapOutput(t->left, depth + 1);
	for (int i = 0; i < depth; i++)
	{
		cout << " ";
	}
	cout << t->x << endl;
	TreapOutput(t->right, depth + 1);
}





int main()
{
	/*int size = 5;
	Node* root = new Node(rng() % 100);
	for (int i = 0; i < size; i++)
	{
		root = Insert(root, rng() % 100);
	}
	TreapOutput(root, 0);*/

	char cmd;
	int cnt;
	cin >> cnt;
	int x;
	Node* t = nullptr;
	//Node* t = root;

	for (int i = 0; i < cnt; i++)
	{
		cin >> cmd;
		if (cmd == '+')
		{
			cin >> x;
			t = Insert(t, x);
		}
		if (cmd == '-')
		{
			cin >> x;
			t = Remove(t, x);
		}
		if (cmd == '?')
		{
			cin >> x;
			if (TreapFind(t, x))
				cout << "YES" << endl;
			else
				cout << "NO" << endl;
		}
		if (cmd == 's')
		{
			if (!t)
			{
				cout << 0 << endl;
			}
			else
				cout << t->tSize << endl;
		}
		if (cmd == 'p')
		{
			TreapOutput(t, 0);
		}
		if (cmd == 'k')
		{
			int k;
			cin >> k;
			Node* xk = kth(t, k);
			if (xk == nullptr)
			{
				cout << "No kth element" << endl;
			}
			else
				cout << xk->x << endl;
		}

	}


	return 0;
}