diff --git a/app/main.py b/app/main.py
index fa56336e..8c3a33d1 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1 +1,37 @@
-# write your code here
+class Animal:
+    alive = []
+
+    def __init__(
+            self,
+            name: str,
+            health: int = 100,
+            hidden: bool = False
+    ) -> None:
+        self.name = name
+        self.health = health
+        self.hidden = hidden
+        Animal.alive.append(self)
+
+    def __repr__(self) -> str:
+        return (
+            f"{{Name: {self.name}, "
+            f"Health: {self.health}, "
+            f"Hidden: {self.hidden}}}"
+        )
+
+    def die(self) -> None:
+        if self in Animal.alive:
+            Animal.alive.remove(self)
+
+
+class Herbivore(Animal):
+    def hide(self) -> None:
+        self.hidden = not self.hidden
+
+
+class Carnivore(Animal):
+    def bite(self, animal: str) -> None:
+        if isinstance(animal, Herbivore) and not animal.hidden:
+            animal.health -= 50
+            if animal.health <= 0:
+                animal.die()