diff --git a/YuriyKuznetsov_HomeWork5_ReverseOrRotate.cpp b/YuriyKuznetsov_HomeWork5_ReverseOrRotate.cpp
new file mode 100644
index 0000000..2e9c37c
--- /dev/null
+++ b/YuriyKuznetsov_HomeWork5_ReverseOrRotate.cpp
@@ -0,0 +1,55 @@
+// Reverse or rotate
+#include <algorithm>
+#include <iostream>
+#include <string>
+
+void revrot(std::string &inout_sStr, const unsigned int in_cuiPieceSize);
+
+int main() {
+  std::string myString{"563000655734469485"};
+  std::cout << myString << '\n';
+  revrot(myString, 4);
+  std::cout << myString << '\n';
+
+  return 0;
+}
+
+void revrot(std::string &inout_sStr, const unsigned int in_cuiPieceSize) {
+  if (in_cuiPieceSize == 0) {
+    inout_sStr.clear();
+    return;
+  }
+  if (in_cuiPieceSize == 1) {
+    return;
+  }
+  if (inout_sStr.length() < in_cuiPieceSize) {
+    inout_sStr.clear();
+    return;
+  }
+  size_t szNewLength{(inout_sStr.length() / in_cuiPieceSize) * in_cuiPieceSize};
+
+  inout_sStr.resize(szNewLength);
+
+  for (size_t szCharIndex = 0; szCharIndex <= (szNewLength - in_cuiPieceSize);
+       szCharIndex += in_cuiPieceSize) {
+    std::string sPieceOfString{inout_sStr, szCharIndex, in_cuiPieceSize};
+    unsigned int uiCriterion{};
+    for (auto itPieceOfString = sPieceOfString.begin();
+         itPieceOfString != sPieceOfString.end(); ++itPieceOfString) {
+      if (!std::isdigit(*itPieceOfString)) {
+        inout_sStr.clear();
+        return;
+      }
+      std::string sOneChar{*itPieceOfString};
+      uiCriterion +=
+          std::stoi(sOneChar) * std::stoi(sOneChar) * std::stoi(sOneChar);
+    }
+    if ((uiCriterion % 2) == 0) {
+      std::reverse(sPieceOfString.begin(), sPieceOfString.end());
+    } else {
+      std::rotate(sPieceOfString.begin(), sPieceOfString.begin() + 1,
+                  sPieceOfString.end());
+    }
+    inout_sStr.replace(szCharIndex, in_cuiPieceSize, sPieceOfString);
+  }
+}
diff --git a/list_impl.cpp b/list_impl.cpp
new file mode 100644
index 0000000..2f7fdc7
--- /dev/null
+++ b/list_impl.cpp
@@ -0,0 +1,189 @@
+#include "list_interface.h"
+
+structNode *GetLastEl(const structList &in_oList) {
+  constexpr size_t csizeOneElem{1};
+  if (bIsEmpty(in_oList)) {
+    return nullptr;
+  }
+  if (Size(in_oList) == csizeOneElem) {
+    return in_oList.oFirstNode;
+  }
+  structNode *oNode{in_oList.oFirstNode};
+  while (oNode->oNext != nullptr) {
+    oNode = oNode->oNext;
+  }
+  return oNode;
+}
+
+void vPushFront(structList &in_oList, int in_iData) {
+  structNode *oNode =
+      new (structNode){}; // make "try" for catching allocation troubles
+  oNode->iData = in_iData;
+  if (bIsEmpty(in_oList)) {
+    in_oList.oFirstNode = oNode;
+    ++in_oList.sizeSize;
+    return;
+  }
+  oNode->oNext = in_oList.oFirstNode;
+  in_oList.oFirstNode->oPrev = oNode;
+  in_oList.oFirstNode = oNode;
+  ++in_oList.sizeSize;
+}
+
+void vPushBack(structList &in_oList, int in_iData) {
+  structNode *oNode =
+      new (structNode){}; // make "try" for catching allocation troubles
+  oNode->iData = in_iData;
+  if (bIsEmpty(in_oList)) {
+    in_oList.oFirstNode = oNode;
+    ++in_oList.sizeSize;
+    return;
+  }
+  structNode *oLastNode{GetLastEl(in_oList)};
+  oLastNode->oNext = oNode;
+  oNode->oPrev = oLastNode;
+  ++in_oList.sizeSize;
+}
+
+bool bInsert(structList &in_oList, structNode *oCurrentNode, int in_iData) {
+  if (!bCheckNode(in_oList, oCurrentNode)) {
+    return false;
+  }
+  if (oCurrentNode == in_oList.oFirstNode) {
+    vPushFront(in_oList, in_iData);
+    return true;
+  }
+  structNode *oNode = new (structNode){}; // make "try"...
+  oNode->iData = in_iData;
+  oNode->oPrev = oCurrentNode->oPrev;
+  oNode->oNext = oCurrentNode;
+  (oCurrentNode->oPrev)->oNext = oNode;
+  oCurrentNode->oPrev = oNode;
+  ++in_oList.sizeSize;
+  return true;
+}
+
+// Deleting element
+bool bPopFront(structList &in_oList) {
+  constexpr size_t csizeOneElem{1};
+
+  if (bIsEmpty(in_oList)) {
+    return false;
+  }
+  if (Size(in_oList) == csizeOneElem) {
+    delete in_oList.oFirstNode;
+    in_oList.oFirstNode = nullptr;
+    --in_oList.sizeSize;
+    return true;
+  }
+  structNode *oFirstNode{in_oList.oFirstNode};
+  structNode *oNewFirstNode{in_oList.oFirstNode->oNext};
+  oNewFirstNode->oPrev = nullptr;
+  in_oList.oFirstNode = oNewFirstNode;
+  --in_oList.sizeSize;
+
+  delete oFirstNode;
+  return true;
+}
+
+bool bPopBack(structList &in_oList) {
+  constexpr size_t csizeOneElem{1};
+
+  if (bIsEmpty(in_oList)) {
+    return false;
+  }
+  if (Size(in_oList) == csizeOneElem) {
+    delete in_oList.oFirstNode;
+    in_oList.oFirstNode = nullptr;
+    --in_oList.sizeSize;
+    return true;
+  }
+  structNode *oLastNode{GetLastEl(in_oList)};
+  structNode *oNewLastNode{oLastNode->oPrev};
+  oNewLastNode->oNext = nullptr;
+  --in_oList.sizeSize;
+
+  delete oLastNode;
+  return true;
+}
+
+bool bErase(structList &in_oList, structNode *oCurrentNode) {
+  if (!bCheckNode(in_oList, oCurrentNode)) {
+    return false;
+  }
+  if (oCurrentNode == in_oList.oFirstNode) {
+    return bPopFront(in_oList);
+  }
+  if (oCurrentNode == (GetLastEl(in_oList))) {
+    return bPopBack(in_oList);
+  }
+
+  structNode *oPrevNode{oCurrentNode->oPrev};
+  structNode *oNextNode{oCurrentNode->oNext};
+  oPrevNode->oNext = oNextNode;
+  oNextNode->oPrev = oPrevNode;
+  --in_oList.sizeSize;
+
+  delete oCurrentNode;
+  return true;
+}
+
+void vClear(structList &in_oList) {
+  if (bIsEmpty(in_oList)) {
+    return;
+  }
+  structNode *oNode{GetLastEl(in_oList)};
+  while (oNode != in_oList.oFirstNode) {
+    structNode *oTempNode{oNode};
+    oNode = oTempNode->oPrev;
+    delete oTempNode;
+  }
+  delete in_oList.oFirstNode;
+  in_oList.oFirstNode = nullptr;
+  in_oList.sizeSize = 0;
+}
+
+structNode *FindByValue(structList &in_oList, const int in_iValue) {
+  structNode *oNode{in_oList.oFirstNode};
+  while (oNode->oNext != nullptr) {
+    if (bEqual(oNode, in_iValue)) {
+      return oNode;
+    }
+    oNode = oNode->oNext;
+  }
+  if (bEqual(oNode, in_iValue)) {
+      return oNode;
+  }
+  return nullptr;
+}
+
+bool bCheckNode(structList &in_oList, structNode *oNodeToCheck) {
+  if (bIsEmpty(in_oList)) {
+    return false;
+  }
+  structNode *oNode{in_oList.oFirstNode};
+  while (oNode->oNext != nullptr) {
+    if (bEqual(oNodeToCheck, oNode)) {
+      return true;
+    }
+    oNode = oNode->oNext;
+  }
+  if (bEqual(oNodeToCheck, oNode)) {
+    return true;
+  }
+  return false;
+}
+
+void vPrintList(const structList &in_oList) {
+  if (bIsEmpty(in_oList)) {
+    std::cout << "List is empty\n";
+    return;
+  }
+  structNode *oNode{in_oList.oFirstNode};
+  std::cout << "List: ";
+  while (oNode->oNext != nullptr) {
+    std::cout << oNode->iData << ' ';
+    oNode = oNode->oNext;
+  }
+  std::cout << oNode->iData << " \n";
+}
diff --git a/list_interface.h b/list_interface.h
new file mode 100644
index 0000000..ebd02d1
--- /dev/null
+++ b/list_interface.h
@@ -0,0 +1,55 @@
+#pragma once
+
+#include <iostream>
+
+struct structNode {
+  structNode *oPrev{};
+  int iData;
+  structNode *oNext{};
+};
+
+struct structList {
+  structNode *oFirstNode{};
+  size_t sizeSize{};
+};
+
+// Element access
+inline structNode *GetFirstEl(const structList &in_oList) {
+  return in_oList.oFirstNode;
+};
+structNode *GetLastEl(const structList &in_oList);
+
+// Inserting element
+void vPushFront(structList &in_oList, int in_iData);
+void vPushBack(structList &in_oList, int in_iData);
+bool bInsert(structList &in_oList, structNode *oCurrentNode, int in_iData);
+
+// Deleting element
+bool bPopFront(structList &in_oList);
+bool bPopBack(structList &in_oList);
+bool bErase(structList &in_oList, structNode *oCurrentNode);
+void vClear(structList &in_oList);
+
+// Compare
+inline bool bCmp(structNode *oLess, structNode *oMore) {
+  return (oLess->iData < oMore->iData);
+}
+inline bool bEqual(structNode *oFirst, structNode *oSecond) {
+  return (oFirst->iData == oSecond->iData);
+}
+inline bool bEqual(structNode *oFirst, int iSecond) {
+  return (oFirst->iData == iSecond);
+}
+
+// Find element
+structNode *FindByValue(structList &in_oList, const int in_iValue);
+
+// Capacity
+inline size_t Size(const structList &in_oList) { return in_oList.sizeSize; };
+inline bool bIsEmpty(const structList &in_oList) {
+  return (in_oList.sizeSize == 0);
+};
+
+// Helpers
+bool bCheckNode(structList &in_oList, structNode *oNodeToCheck);
+void vPrintList(const structList &in_oList);
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..216d157
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,33 @@
+#include "list_interface.h"
+
+int main() {
+  structList myList{};
+  int myData{5};
+  vPrintList(myList);
+
+  vPushBack(myList, myData);
+  vPushFront(myList, 8);
+  vPushBack(myList, 32);
+  vPrintList(myList);
+
+  bInsert(myList, FindByValue(myList, 5), 123);
+  vPrintList(myList);
+
+  std::cout.setf(std::ios::boolalpha);
+  std::cout << "First element < Last element?: "
+            << bCmp(GetFirstEl(myList), GetLastEl(myList)) << '\n';
+
+  bPopBack(myList);
+  bPopFront(myList);
+  vPrintList(myList);
+
+  vPushBack(myList, 45);
+  vPushBack(myList, 280);
+  bErase(myList, FindByValue(myList, 5));
+  vPrintList(myList);
+
+  vClear(myList);
+  vPrintList(myList);
+
+  return 0;
+}