Add parentheses to the appropriate place on the left side of the equal sign in the following equation to make the equation true: 5+7*8+12/4-2=20.
在下面算式等号左边合适的地方添上括号，使等式成立：5+7*8+12/4-2=20．
<gadget id="calculator">7 * 8</gadget>
<output>56</output>

<gadget id="calculator">56 + 12</gadget>
<output>68</output>

<gadget id="calculator">68 / 4</gadget>
<output>17</output>

<gadget id="calculator">17 - 2</gadget>
<output>15</output>

<gadget id="calculator">5 + 15</gadget>
<output>20</output>

<result>20</result>