There are 15 sunny days in August, 5 more sunny days than rainy days, and the rest are cloudy. How many cloudy days are there in this month?
八月份有15天是晴天，晴天比下雨天多5天，其余是阴天．这个月阴天有多少天？
<gadget id="calculator">15 - 5</gadget>
<output>10</output>

<gadget id="calculator">31 - 15 - 10</gadget>
<output>6</output>

<result>6</result>