diff --git a/app/main.py b/app/main.py
index fa56336e..62569ef8 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1 +1,32 @@
-# write your code here
+class Animal:
+
+    alive = []
+
+    def __init__(self, name: str, health: int = 100) -> None:
+        self.name = name
+        self.health = health
+        self.hidden = False
+        Animal.alive.append(self)
+
+    def decrease_health(self, amount: int) -> None:
+        self.health -= amount
+        if self.health <= 0:
+            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):
+
+    def bite(self, herbivore: Herbivore) -> None:
+        if isinstance(herbivore, Carnivore) or herbivore.hidden:
+            return
+        herbivore.decrease_health(50)