diff --git a/app/main.py b/app/main.py
index fa56336e..9072e2c6 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1 +1,27 @@
-# write your code here
+class Animal:
+    alive = []
+
+    def __init__(self, name: str, health: int = 100,
+                 hidden: bool = False) -> None:
+        self.health = health
+        self.name = name
+        self.hidden = hidden
+        Animal.alive.append(self)
+
+    def __repr__(self) -> str:
+        return (f"{{Name: {self.name}, Health: {self.health}, "
+                f"Hidden: {self.hidden}}}")
+
+
+class Herbivore(Animal):
+    def hide(self) -> None:
+        self.hidden = not self.hidden
+
+
+class Carnivore(Animal):
+    def bite(self, animal: Animal) -> None:
+        if (not animal.hidden and animal in animal.alive
+                and isinstance(animal, Herbivore)):
+            animal.health -= 50
+            if animal.health <= 0:
+                Animal.alive.remove(animal)