diff --git a/bst.cpp b/bst.cpp
new file mode 100644
index 0000000..47cd411
--- /dev/null
+++ b/bst.cpp
@@ -0,0 +1,167 @@
+#include<iostream>
+#include<string>
+#include<cassert>
+#include<sstream>
+using namespace std;
+
+
+class CTree{
+public:
+    CTree() = default;
+    CTree(const CTree & src) = delete;
+    CTree & operator = (const CTree & src) = delete;
+    
+    ~CTree(){
+        delete m_Root;
+    }
+
+    bool isSet(const string & key){
+        CNode* i = nullptr;
+        CNode* n = m_Root;
+        do {
+            std::swap(i, n);
+            if (i->m_Key == key) return true;
+            n = i->m_Key < key ? i->m_R : i->m_L;
+        } while (n);
+        return false;
+    }
+    
+    bool insert(const string & key, const string & val){
+        if (!m_Root) {
+            m_Root = new CNode(key, val);
+            m_First = m_Last = m_Root;
+            return true;
+        }
+
+        CNode* i = nullptr;
+        CNode* n = m_Root;
+        do {
+            std::swap(i, n);
+            if (i->m_Key == key) return false;
+            n = i->m_Key < key ? i->m_R : i->m_L;
+        } while (n);
+        n = new CNode(key, val);
+
+
+        if (i->m_Key < key) {
+            i->m_R = n;
+        } else {
+            i->m_L = n;
+        }
+
+        return m_Last = m_Last->m_NextOrder = n;
+    }
+    
+    friend ostream & operator << (ostream & os, const CTree & src){
+        src.print(os);
+        return os;
+    }
+
+protected:
+
+    class CNode{
+    public:
+        CNode(const string & key, const string & val)
+        :m_Key(key), m_Val(val) {}
+        ~CNode() {
+            delete m_L;
+            delete m_R;
+        }
+        string m_Key, m_Val;
+        CNode * m_L = nullptr, * m_R = nullptr; 
+        CNode * m_NextOrder = nullptr;  
+    };
+
+    CNode * m_Root = nullptr;
+    CNode * m_First = nullptr, * m_Last = nullptr;
+
+    void print( ostream & os ) const {
+        os << "{";
+        for (CNode* i = m_First; i; i = i->m_NextOrder) {
+            os << i->m_Key << " => " << i->m_Val;
+            if (i != m_Last) os << ", ";
+        }
+        os << "}";
+    }
+
+    friend int main();
+};
+ 
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+int main(void){
+    CTree t;
+    stringstream ss;
+    ss << t;
+    assert(ss.str() == "{}");
+    ss.clear();
+    ss.str(""); 
+    assert(t.insert("PA1", "done"));
+    assert(t.m_First == t.m_Last);
+    assert(t.m_First->m_Key == "PA1");
+    assert(!t.isSet("UOS"));
+    assert(t.insert("PA2", "fail"));
+    assert(t.insert("UOS", "funny"));
+ 
+    ss << t;
+    assert(ss.str() == "{PA1 => done, PA2 => fail, UOS => funny}");
+    ss.clear();
+    ss.str("");
+ 
+ 
+    assert(t.m_Root->m_L== nullptr);
+    assert(t.m_Last->m_Key == "UOS");
+    assert(t.m_Root->m_R->m_Key == "PA2");
+    assert(t.m_Root->m_R->m_L == nullptr);
+    assert(t.m_Root->m_R->m_R->m_Key == "UOS");
+    assert(t.m_First->m_NextOrder->m_NextOrder == t.m_Last);
+    assert(t.isSet("PA2"));
+ 
+    assert(t.insert("CAO", "lul"));
+    assert(t.insert("LIN", "F"));
+    assert(t.m_Root->m_L->m_Key == "CAO");
+    assert(t.m_Root->m_L->m_L == nullptr);
+    assert(t.m_Root->m_L->m_R->m_Key == "LIN");
+    assert(t.m_Last == t.m_Root->m_L->m_R );
+    assert(t.m_Root->m_L->m_R->m_L == nullptr);
+    assert(t.m_First->m_NextOrder->m_NextOrder->m_NextOrder->m_NextOrder = t.m_Root->m_L->m_R);
+    assert(t.isSet("LIN"));
+ 
+    ss << t;
+    assert(ss.str() == "{PA1 => done, PA2 => fail, UOS => funny, CAO => lul, LIN => F}");
+    ss.clear();
+    ss.str("");
+ 
+    assert(t.insert("SAP", "shit"));
+    assert(t.m_Root->m_R->m_R->m_L->m_Key == "SAP");
+    assert(t.m_Last == t.m_Root->m_R->m_R->m_L);
+ 
+ 
+    ss << t;
+    assert(ss.str() == "{PA1 => done, PA2 => fail, UOS => funny, CAO => lul, LIN => F, SAP => shit}");
+    ss.clear();
+    ss.str("");
+ 
+    assert(!t.isSet("PA3"));
+    assert(t.isSet("LIN"));
+    assert(t.isSet("SAP"));
+ 
+    std::cout << "success!\n";
+    return 0;
+}
\ No newline at end of file