diff --git a/Implement-Laptop-Allocation/implementLaptop.py b/Implement-Laptop-Allocation/implementLaptop.py
new file mode 100644
index 0000000..fa0fc03
--- /dev/null
+++ b/Implement-Laptop-Allocation/implementLaptop.py
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+from dataclasses import dataclass
+from enum import Enum
+from typing import List, Dict
+
+
+# Define possible operating systems
+class OperatingSystem(Enum):
+    MACOS = "macOS"
+    ARCH = "Arch Linux"
+    UBUNTU = "Ubuntu"
+
+
+# Define Person and Laptop
+@dataclass
+class Person:
+    name: str
+    age: int
+    preferred_operating_system: List[OperatingSystem]
+
+
+@dataclass
+class Laptop:
+    id: int
+    manufacturer: str
+    model: str
+    operating_system: OperatingSystem
+
+
+# Function to calculate sadness
+def sadness_for_person(person: Person, laptop: Laptop) -> int:
+    """How sad a person is with this laptop."""
+    if laptop.operating_system in person.preferred_operating_system:
+        return person.preferred_operating_system.index(laptop.operating_system)
+    else:
+        return 100  # Very sad if OS not in their list
+
+
+# Simple laptop allocation
+def allocate_laptops(people: List[Person], laptops: List[Laptop]) -> Dict[str, Laptop]:
+    """
+    Give each person one laptop.
+    Try to reduce sadness.
+    """
+    allocated = {}
+    available_laptops = laptops.copy()
+
+    for person in people:
+        best_laptop = None
+        best_sadness = 999
+
+        # Try to find the best laptop for this person
+        for laptop in available_laptops:
+            s = sadness_for_person(person, laptop)
+            if s < best_sadness:
+                best_sadness = s
+                best_laptop = laptop
+
+        # Give them the best one we found
+        allocated[person.name] = best_laptop
+        available_laptops.remove(best_laptop)
+
+    return allocated
+
+
+# Testing data
+def main():
+    laptops = [
+        Laptop(1, "Dell", "XPS 13", OperatingSystem.ARCH),
+        Laptop(2, "Dell", "XPS 15", OperatingSystem.UBUNTU),
+        Laptop(3, "Apple", "MacBook Air", OperatingSystem.MACOS),
+        Laptop(4, "Dell", "Inspiron", OperatingSystem.UBUNTU),
+    ]
+
+    people = [
+        Person("Imran", 22, [OperatingSystem.UBUNTU, OperatingSystem.ARCH, OperatingSystem.MACOS]),
+        Person("Eliza", 34, [OperatingSystem.ARCH, OperatingSystem.UBUNTU, OperatingSystem.MACOS]),
+        Person("Sam", 29, [OperatingSystem.MACOS, OperatingSystem.UBUNTU]),
+        Person("Tariq", 25, [OperatingSystem.ARCH]),
+    ]
+
+    allocations = allocate_laptops(people, laptops)
+
+    print("=== Laptop Allocations ===")
+    total_sadness = 0
+    for name, laptop in allocations.items():
+        person = next(p for p in people if p.name == name)
+        sad = sadness_for_person(person, laptop)
+        total_sadness += sad
+        print(f"{name} gets {laptop.model} ({laptop.operating_system.value}) - sadness {sad}")
+
+    print(f"\nTotal sadness: {total_sadness}")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/Prep Exercises/enums.py b/Prep Exercises/enums.py
new file mode 100644
index 0000000..c4e834a
--- /dev/null
+++ b/Prep Exercises/enums.py	
@@ -0,0 +1,89 @@
+from enum import Enum
+import sys
+
+# Define the possible operating systems as an enum
+class OperatingSystem(Enum):
+    MACOS = "MacOS"
+    ARCH = "Arch"
+    UBUNTU = "Ubuntu"
+
+# List of laptops available in the library
+laptops = [
+    {"id": 1, "manufacturer": "Dell", "model": "XPS", "os": OperatingSystem.ARCH},
+    {"id": 2, "manufacturer": "Dell", "model": "XPS", "os": OperatingSystem.UBUNTU},
+    {"id": 3, "manufacturer": "Dell", "model": "XPS", "os": OperatingSystem.UBUNTU},
+    {"id": 4, "manufacturer": "Apple", "model": "MacBook", "os": OperatingSystem.MACOS},
+    {"id": 5, "manufacturer": "Dell", "model": "Inspiron", "os": OperatingSystem.UBUNTU},
+]
+
+def get_user_preferences():
+    """Get the user's name and preferred operating system"""
+    name = input("Enter your name: ").strip()
+    if not name:
+        print("Error: Name cannot be empty", file=sys.stderr)
+        sys.exit(1)
+    
+    print("\nAvailable operating systems:")
+    print("• MacOS")
+    print("• Arch") 
+    print("• Ubuntu")
+    
+    os_choice = input("Enter your preferred operating system: ").strip().lower()
+    
+    # Convert string to OperatingSystem enum
+    if os_choice == "macos":
+        return name, OperatingSystem.MACOS
+    elif os_choice == "arch":
+        return name, OperatingSystem.ARCH
+    elif os_choice == "ubuntu":
+        return name, OperatingSystem.UBUNTU
+    else:
+        print(f"Error: '{os_choice}' is not a valid operating system", file=sys.stderr)
+        print("Please choose from: macos, arch, ubuntu", file=sys.stderr)
+        sys.exit(1)
+
+def count_laptops_by_os():
+    """Count how many laptops we have for each operating system"""
+    counts = {}
+    for os in OperatingSystem:
+        counts[os] = 0
+    
+    for laptop in laptops:
+        counts[laptop["os"]] += 1
+    
+    return counts
+
+def main():
+    print("=== Library Laptop Finder ===")
+    
+    # Get user input
+    name, preferred_os = get_user_preferences()
+    
+    # Count laptops for each OS
+    os_counts = count_laptops_by_os()
+    
+    # Show results to user
+    user_laptop_count = os_counts[preferred_os]
+    
+    print(f"\nHello {name}!")
+    print(f"We have {user_laptop_count} laptop(s) with {preferred_os.value}.")
+    
+    # Check if other OS have more laptops
+    other_options = []
+    for os, count in os_counts.items():
+        if os != preferred_os and count > user_laptop_count:
+            other_options.append((os, count))
+    
+    if other_options:
+        print("\nTip: These operating systems have more laptops available:")
+        for os, count in other_options:
+            print(f"  • {os.value}: {count} laptops")
+    
+    # Show complete availability
+    print(f"\nAll available laptops:")
+    for os in OperatingSystem:
+        count = os_counts[os]
+        print(f"  • {os.value}: {count} laptop(s)")
+
+if __name__ == "__main__":
+    main()
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diff --git a/Prep Exercises/inheritance.py b/Prep Exercises/inheritance.py
new file mode 100644
index 0000000..e11b541
--- /dev/null
+++ b/Prep Exercises/inheritance.py	
@@ -0,0 +1,37 @@
+class Parent:
+    def __init__(self, first_name: str, last_name: str):
+        self.first_name = first_name
+        self.last_name = last_name
+
+    def get_name(self) -> str:
+        return f"{self.first_name} {self.last_name}"
+
+
+class Child(Parent):
+    def __init__(self, first_name: str, last_name: str):
+        super().__init__(first_name, last_name)
+        self.previous_last_names = []
+
+    def change_last_name(self, last_name) -> None:
+        self.previous_last_names.append(self.last_name)
+        self.last_name = last_name
+
+    def get_full_name(self) -> str:
+        suffix = ""
+        if len(self.previous_last_names) > 0:
+            suffix = f" (née {self.previous_last_names[0]})"
+        return f"{self.first_name} {self.last_name}{suffix}"
+
+person1 = Child("Elizaveta", "Alekseeva")
+print(person1.get_name())
+print(person1.get_full_name())
+person1.change_last_name("Tyurina")
+print(person1.get_name())
+print(person1.get_full_name())
+
+person2 = Parent("Elizaveta", "Alekseeva")
+print(person2.get_name())
+# print(person2.get_full_name())
+# person2.change_last_name("Tyurina")
+print(person2.get_name())
+# print(person2.get_full_name())
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