The high-quality fashion factory produced 18 million sets of clothing in the first half of last year, and completed 75% of the planned output in the second half of the year, so that the annual output exceeded 12.5% of the planned output. How many thousand sets of clothing did it plan to produce last year?
高质时装厂去年上半年生产服装1800万套，下半年完成计划产量的75%，这样全年超过计划产量的12.5%，去年计划生产服装多少万套？
<gadget id="calculator">12.5 / 100</gadget>
<output>0.125</output>

<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">0.125 - (3/4)</gadget>
<output>-0.625</output>

<gadget id="calculator">1 + (-0.625)</gadget>
<output>0.375</output>

<gadget id="calculator">1_800 / 0.375</gadget>
<output>4_800</output>

<result>4_800</result>