Simple String Compression Algorithm in C#

void Main()
{
	string str = "A-A01A05-A01-01-02";
	byte[] data = new byte[16];
	var span = data.AsSpan();
	
	ulong l = 0;
	int index = 1;
	int count = 0;
	for (int i = 0; i < str.Length; i++)
	{
		var value = HashFind.GetValue(str[i]);
		if (index <= 10)
		{
			l <<= 6;
			l = l | value;
			index++;
		}
		if (index == 11 || i + 1 >= str.Length)
		{
			BinaryPrimitives.TryWriteUInt64LittleEndian(span[count..(count + 8)], l);
			l = 0;
			index = 1;
			count += 8;
		}
	}
	Console.WriteLine(BinaryPrimitives.ReadInt64LittleEndian(data[0..8]));
	Console.WriteLine(BinaryPrimitives.ReadInt64LittleEndian(data[8..16]));
}

public static class HashFind
{
	private const byte A = (byte)'A';      // 65
	private const byte Z = (byte)'Z';      // 90
	private const byte Zero = (byte)'0';   // 48
	private const byte Nine = (byte)'9';   // 57

	//private static readonly char[] Dic = new char[] {'0','1','2','3','4','5','6','7','8','9',
	//							 'A', 'B', 'C', 'D', 'D', 'E', 'E', 'E',
	//							 'E', 'F', 'G', 'H', 'H', 'I', 'J', 'K',
	//							 'L', 'M', 'N', 'O', 'O', 'O', 'O', 'P',
	//							 'Q', 'R', 'R', 'T', 'U', 'U', 'V', 'W',
	//							 'X', 'Y', 'Z','-'};

	public static byte GetValue(char ch)
	{
		if (ch.Equals('-')) return (byte)36;
		var upper = char.ToUpper(ch);
		var value = (byte)upper;
		// 0-9
		if (Zero <= value && value <= Nine)
		{
			return (byte)(value - Zero);
		}
		// 10-35
		else if (A <= value && value <= Z)
		{
			return (byte)(value - A + (byte)10);
		}
		throw new InvalidDataException("Character value is out of range");
	}
}