A certain elementary school held an autumn sports meeting. There were 37 participants in the third grade, twice as many participants in the fourth grade, and 15 fewer participants in the fifth grade than the total number of participants in the third and fourth grades. How many students in grades 3, 4, and 5 will participate?
某小学举办秋季运动会，三年级有37人参加，四年级参加的人数是三年级的2倍，五年级参加的人数比三、四年级参加的总人数少15人．三、四、五年级一共有多少人参加？
<gadget id="calculator">37 * 2</gadget>
<output>74</output>

<gadget id="calculator">74 - 15</gadget>
<output>59</output>

<gadget id="calculator">37 + 59</gadget>
<output>96</output>

<gadget id="calculator">37 + 74 + 96</gadget>
<output>207</output>

<result>207</result>