Adult tickets for the museum are 5 yuan each, two adults can bring a child for free, child tickets are 4 yuan each, and if you buy a joint ticket for a group of 5, each ticket is 3.8 yuan. There are currently 3 teachers and 14 children participating. How much is the minimum cost?
博物馆成人门票每张5元，两名成人可免费带一名儿童，儿童票每张4元，如果买5人一组的联票，每张3.8元．现有3名老师和14名小朋友来参加，最少要花多少元？
<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<gadget id="calculator">3.8 * 10</gadget>
<output>38</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">10 + 38 + 16</gadget>
<output>64</output>

<result>64</result>