Tickets for a museum are priced at RMB 5 for adults and RMB 4 for children. Two adults who buy full tickets can bring a child into the museum for free. Any group of five people can purchase special tickets with a total price of RMB 19. There are 3 adults and 14 children who want to visit the museum. What is the minimum cost for them to buy tickets?
某博物馆的门票售价为：成人票5元，孩童票4元，二位购买全票的成人可免费带一位小孩入馆，任何五个人的团体可以购买总价为19元的特价门票．现有三位成人带领十四位小孩欲进馆参观，请问他们购买门票至少要花费多少元？
<gadget id="calculator">19 * 2</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>