Xiao Li compiled a program, the output number is the square of his input number minus 1, after he input 2.25, input the output result again, find the output number on the screen now.
小李编了一个程序，输出的数是他输入数的平方减1，他输入2.25后，输出的结果再输入，求现在屏幕上输出的数．
<gadget id="calculator">2.25 ** 2</gadget>
<output>5.0625</output>

<gadget id="calculator">5.0625 - 1</gadget>
<output>4.0625</output>

<gadget id="calculator">4.0625 ** 2</gadget>
<output>16.503906</output>

<gadget id="calculator">16.503906 - 1</gadget>
<output>15.503906</output>

<result>15.503906</result>