std::string encodedDigit(char letter) const
	{
		const std::unordered_map<char, std::string> encodings
		{
			{'b', "1"}, {'f', "1"}, {'p', "1"}, {'v', "1"},
			{'c', "2"}, {'g', "2"}, {'j', "2"}, {'k', "2"}, {'q', "2"},
						{'s', "2"}, {'x', "2"}, {'z', "2"},
			{'d', "3"}, {'t', "3"},
			{'l', "4"},
			{'m', "5"}, {'n', "5"},
			{'r', "6"}
		};
		return encodings.find(letter)->second;
	}