Operating Expenses	2017	2018	2019	2020
Sales and marketing expenses	232,489	585,758	1,198,516	3,492,091
Sales and marketing expenses	30.1%	37.0%	44.6%	58.4%
General and administrative expenses	260,898	461,165	592,497	976,082
General and administrative expenses	33.7%	29.1%	22.1%	16.3%
Research and development expenses	280,093	537,488	894,411	1,512,966
Research and development expenses	36.2%	33.9%	33.3%	25.3%