The number of willow trees in the park is 49 times less than that of pine trees, and there are 85 pine trees. How many willow trees are there?
公园里柳树的棵数是松树的2倍少49棵，松树有85棵，柳树有多少棵？
<gadget id="calculator">85 * 2</gadget>
<output>170</output>

<gadget id="calculator">170 - 49</gadget>
<output>121</output>

<result>121</result>