diff --git a/app/main.py b/app/main.py
index fa56336e..ca0b2209 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1 +1,33 @@
-# write your code here
+from typing import List, Union
+
+
+class Animal:
+    alive: List["Animal"] = []
+
+    def __init__(self, name: str) -> None:
+        self.name: str = name
+        self.health: int = 100
+        self.hidden: bool = False
+        Animal.alive.append(self)
+
+    def die(self) -> None:
+        Animal.alive.remove(self)
+
+    def __repr__(self) -> str:
+        return f"{{Name: {self.name}, " \
+               f"Health: {self.health}, " \
+               f"Hidden: {self.hidden}}}"
+
+
+class Herbivore(Animal):
+    def hide(self) -> None:
+        self.hidden = not self.hidden
+
+
+class Carnivore(Animal):
+    @staticmethod
+    def bite(target: Union[Herbivore, "Carnivore"]) -> None:
+        if isinstance(target, Herbivore) and not target.hidden:
+            target.health -= 50
+            if target.health <= 0:
+                target.die()