The first merchant bought half of the flock (1/8) from him, the second merchant bought the rest (1/6) and half from him, and the third merchant bought the remaining sheep from him. The next (1/4) took half of the sheep, and the last merchant bought the remaining half and took half of the sheep. At this time, Avanti’s sheep were all sold out. How many sheep did he have at least? (Reverse Thinking)
第一个商人向他买去这群羊的(1/8)带半只，第二个商人向他买去剩下的(1/6)带半只，第三个商人向他买去剩下的(1/4)带半只，最后一个商人买走了剩下的一半带半只，这时阿凡提的羊全部卖完了，他原来最少有几只羊？(逆向思维)
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/2) / (3/4)</gadget>
<output>2</output>

<gadget id="calculator">2 + (1/2)</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(5/2) / (5/6)</gadget>
<output>3</output>

<gadget id="calculator">3 + (1/2)</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 - (1/8)</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">(7/2) / (7/8)</gadget>
<output>4</output>

<result>4</result>