#include <iostream>
#include<string>

using namespace std;

struct Node {
    Node *l, *r;
    long long key, pr;
    Node(int x) : key(x), pr(rand()), l(nullptr), r(nullptr) {}
};

Node* merge(Node* L, Node* R) {
    if (L == nullptr) return R;
    if (R == nullptr) return L;
    if (L->pr > R->pr) {
        L->r = merge(L->r, R);
        return L;
    }
    R->l = merge(L, R->l);
    return R;
}

pair < Node*, Node* > split(Node* tree, int k) {
    if (tree == nullptr) return {nullptr, nullptr};
    if (tree->key <= k) {
        pair < Node*, Node* > p = split(tree->r, k);
        tree->r = p.first;
        return {tree, p.second};
    }
    auto p = split(tree->l, k);
    tree->l = p.second;
    return {p.first, tree};
}

Node* insert(Node* tree, int k) {
    auto p = split(tree, k);
    Node* v = new Node(k);
    return merge(merge(p.first, v), p.second);
}

Node* erase(Node* tree, int k) {
    if (tree == nullptr) return tree;
    if (tree->key == k) return merge(tree->l, tree->r);
    if (tree->key < k) {
        tree->r = erase(tree->r, k);
    } else {
        tree->l = erase(tree->l, k);
    }
    return tree;
}

bool search(Node* tree, int k) {
    if (tree == nullptr) return false;
    if (tree->key == k) return true;
    if (tree->key < k) return search(tree->r, k);
    return search(tree->l, k);
}

int main() {
    Node *root = nullptr;
    string s;
    long long k;
    while (cin >> s) {
        cin >> k;
        if (s == "insert") {
            bool f = search(root, k);
            if (!f) root = insert(root, k);
        } else if (s == "delete") {
            bool f = search(root, k);
            if (f) root = erase(root, k);
        } else {
            bool f = search(root, k);
            if(f) cout << "true" << endl;
            else cout << "false" << endl;
        }
    }
    return 0;
}