diff --git a/7-3/main.cpp b/7-3/main.cpp
index 8b13789..bf0c7bf 100644
--- a/7-3/main.cpp
+++ b/7-3/main.cpp
@@ -1 +1,172 @@
+/*
+Порядковые статистики. Дано число N и N строк. Каждая строка содержит команду добавления или удаления натуральных чисел, 
+а также запрос на получение k-ой порядковой статистики. Команда добавления числа A задается положительным числом A, 
+команда удаления числа A задается отрицательным числом “-A”. Запрос на получение k-ой порядковой статистики задается числом k.
+
+Вариант 7_3.  Требуемая скорость выполнения запроса - O(log n) в среднем. В реализации используйте декартово дерево.
+*/
+
+#include <cassert>
+#include <iostream>
+#include <string>
+#include <memory.h>
+#include <stdint.h>
+#include <vector>
+#include <queue>
+#include <ctime>
+#include <math.h>
+
+using namespace std;
+
+struct Node {
+    int value;
+    int priority;
+    int count;
+    Node* left = nullptr;
+    Node* right = nullptr;
+    Node(int value_, int priority_) : value(value_), priority(priority_), count(1) {}
+};
+
+class Treap {
+public:
+    Treap() = default;
+    Treap(const Treap&) = delete;
+    Treap(const Treap&&) = delete;
+    Treap& operator= (const Treap&) = delete;
+    Treap& operator= (const Treap&&) = delete;
+    ~Treap();
+    
+    void pre_order_print() const;
+    void insert(int key, int priority);
+    void erase(int key);
+    int kth_largest(int idx);
+    
+private:
+    Node* root = nullptr;
+    void split(Node* node, int key, Node*& left, Node*& right);
+    Node* merge(Node* left, Node* right);
+    Node* kth_largest_(int idx, Node* node);
+    int get_count(Node* node) {return (node) ? node->count : 0; }
+    void update_count(Node* node) {
+        if (node) {
+            node->count = get_count(node->left) + get_count(node->right) + 1;
+        }
+    }
+};
+
+void Treap::pre_order_print() const {
+    Node* current = root;
+    vector<Node *> stack;
+    while (current || !stack.empty()) {
+        if (current) {
+            cout << current->value << ' ' << current->count << endl;
+            stack.push_back(current);
+            current = current->left;
+            }
+        else {
+            current = stack.back()->right;
+            stack.pop_back();
+        }
+    }
+    cout << endl;
+}
+
+void Treap::split(Node* node, int key, Node*& left, Node*& right) {
+    if (!node) {
+        left = right = nullptr;
+    } else if (node->value <= key){
+        split(node->right, key, node->right, right);
+        left = node;
+    } else {
+        split(node->left, key, left, node->left);
+        right = node;
+    }
+    update_count(node);
+}
+Node* Treap::merge(Node *left, Node *right) {
+    if (!left || !right) { return left == 0 ? right : left; }
+    if (left->priority > right->priority) {
+        left->right = merge(left->right, right);
+        update_count(left);
+        return left;
+    } else {
+        right->left = merge(left, right->left);
+        update_count(right);
+        return right;
+    }
+}
+
+//Реализация вставки номер 2
+void Treap::insert(int key, int priority) {
+    if (!root) {
+        root = new Node(key, priority);
+        return;
+    }
+    
+    Node* new_node = new Node(key, priority);
+    Node* current = root;
+    Node* parent = nullptr;
+    while (current && current->priority >= priority) {
+        parent = current;
+        current = (current->value <= key) ? current->right : current->left;
+        parent->count += 1;
+    }
+    split(current, key, new_node->left, new_node->right);
+    new_node->count += get_count(new_node->left) + get_count(new_node->right);
+    if ( !parent )  {
+        root = new_node;
+        return;
+    }
+    (parent->value <= key) ? parent->right = new_node : parent->left = new_node;
+}
+//Реализация удаления номер 1
+void Treap::erase(int key) {
+    Node* node_to_delete = nullptr;
+    Node* left = nullptr;
+    Node* right = nullptr;
+    split(root, key, left, right);
+    split(left, key-0.5, left ,node_to_delete);
+    root = merge(left, right);
+    delete node_to_delete;
+}
+
+Node* Treap::kth_largest_(int idx, Node* node) {
+    if ( get_count(node->left) < idx ) {
+        return kth_largest_( idx-get_count(node->left)-1, node->right );
+    } else if ( get_count(node->left) > idx ) {
+        return kth_largest_( idx, node->left );
+    } else return node;
+}
+
+int Treap::kth_largest(int idx) {
+    Node* node = kth_largest_(idx, root);
+    return node->value;
+}
+
+Treap::~Treap() {
+    if (!root) return;
+    queue<Node* > q;
+    q.push(root);
+    while (!q.empty()) {
+        Node *node = q.front();
+        q.pop();
+        if (node->left != nullptr) q.push(node->left);
+        if (node->right != nullptr) q.push(node->right);
+        delete node;
+    }
+}
+
+int main() {
+    int N;
+    Treap treap;
+    cin >> N;
+    for (int i = 0; i < N; ++i) {
+        int A, k;
+        cin >> A >> k;
+        int priority = rand() % 1000000;
+        (A > 0) ? treap.insert(abs(A), priority) : treap.erase(abs(A));
+        cout << treap.kth_largest(k) << endl;
+    }
+    cout << endl;
+}