There are 10 2-cent coins and 10 5-cent coins, how many denominations can be formed by using these coins?
有10个2分硬币和10个5分硬币，用这些硬币可以构成的币值有多少种．
<gadget id="calculator">5 * 10</gadget>
<output>50</output>

<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<gadget id="calculator">50 + 16</gadget>
<output>66</output>

<result>66</result>