Calculation: 9+99+999+9999+99999+9999999.
计算：9+99+999+9999+99999+9999999．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">100 - 1</gadget>
<output>99</output>

<gadget id="calculator">1_000 - 1</gadget>
<output>999</output>

<gadget id="calculator">10_000 - 1</gadget>
<output>9_999</output>

<gadget id="calculator">100_000 - 1</gadget>
<output>99_999</output>

<gadget id="calculator">10_000_000 - 1</gadget>
<output>9_999_999</output>

<gadget id="calculator">9 + 99 + 999 + 9_999 + 99_999 + 9_999_999</gadget>
<output>10_111_104</output>

<result>10_111_104</result>