class Base64:
    def __init__(self):
        # Base64 alphabet
        self.alphabet = (
            "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
        )

    def encode(self, data: str) -> str:
        # Convert string to bytes and get binary representation
        binary = "".join([format(b, "08b") for b in data.encode()])

        # Pad with zeros if necessary
        padding = len(binary) % 6
        if padding:
            binary += "0" * (6 - padding)

        # Split into 6-bit chunks and convert to decimal
        chunks = [binary[i : i + 6] for i in range(0, len(binary), 6)]
        result = "".join(self.alphabet[int(chunk, 2)] for chunk in chunks)

        # Add padding characters
        padding = len(data) % 3
        if padding:
            result += "=" * (3 - padding)

        return result

    def decode(self, data: str) -> str:
        # Remove padding characters
        data = data.rstrip("=")

        # Convert to binary
        binary = "".join([format(self.alphabet.index(c), "06b") for c in data])

        # Remove padding zeros
        padding = len(binary) % 8
        if padding:
            binary = binary[:-padding]

        # Convert binary to bytes and then to string
        bytes_data = [int(binary[i : i + 8], 2) for i in range(0, len(binary), 8)]
        return bytes(bytes_data).decode()


# Example usage
def example():
    b64 = Base64()
    original = "Hello, World!"
    encoded = b64.encode(original)
    print(f"Original: {original}")
    print(f"Encoded: {encoded}")


if __name__ == "__main__":
    example()