The side lengths of an isosceles triangle are 1 and 2, what is its perimeter?
等腰三角形的边长为1和2，那么它的周长为多少
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">2 + 2 + 1</gadget>
<output>5</output>

<result>5</result>