The "Three Small" competition was held in Ruian City, and a total of 212 entries were received, including 104 "small productions", 4 less than twice as many as "small inventions". How many "small inventions" are there?
瑞安市举行"三小"比赛，共收到参赛作品212件，其中"小制作"104件，比"小发明"的2倍少4件，"小发明"多少件？
<gadget id="calculator">104 + 4</gadget>
<output>108</output>

<gadget id="calculator">108 / 2</gadget>
<output>54</output>

<result>54</result>