from collections import OrderedDict

class LRUCache:
    def __init__(self, capacity: int):
        self.cache = OrderedDict() # Stores key-value pairs
        self.capacity = capacity   # Maximum number of items in cache

    def get(self, key: str) -> str or None:
        if key not in self.cache:
            return None
        # Move the accessed item to the end (most recently used)
        value = self.cache.pop(key)
        self.cache[key] = value
        return value

    def put(self, key: str, value: str) -> None:
        if key in self.cache:
            self.cache.pop(key) # Remove existing item to update its position
        elif len(self.cache) >= self.capacity:
            # If cache is full, remove the least recently used item (first item)
            self.cache.popitem(last=False)
        self.cache[key] = value # Add or update item at the end (most recently used)

    def __repr__(self):
        return str(self.cache)

# Example Usage:
cache = LRUCache(capacity=3)

cache.put("A", "Value A")
cache.put("B", "Value B")
cache.put("C", "Value C")
print(f"Cache state 1: {cache}")

cache.get("B") # Access B, making it most recently used
print(f"Cache state 2 (accessed B): {cache}")

cache.put("D", "Value D") # Add D, C should be removed as it's least recently used
print(f"Cache state 3 (added D): {cache}")

print(f"Getting A: {cache.get('A')}") # A should exist
print(f"Getting C: {cache.get('C')}") # C should be None
print(f"Cache state 4 (accessed A): {cache}")