The difference between the quotient of a number divided by 5 and divided by 3 is 4, and the remainder is 1. Find this number.
一个数除以5与除以3的商相差4，余数都是1，求这个数．
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">1 - 1</gadget>
<output>0</output>

<gadget id="calculator">20 + 0</gadget>
<output>20</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

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

<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">30 + 1</gadget>
<output>31</output>

<result>31</result>