Last year, a piece of agricultural and sideline products "Zhangsheng", among which "Duck Tongue" (duck tongue) sold for 105 yuan per kilogram, 39 yuan less than twice the original price. How much is the original price per kilogram?
去年，农副产品"涨声"一片，其中"鸭扁你"(鸭舌)每千克卖到105元，比原价的2倍少39元．原价每千克多少元？
<gadget id="calculator">105 + 39</gadget>
<output>144</output>

<gadget id="calculator">144 / 2</gadget>
<output>72</output>

<result>72</result>