For any natural number, define n! =1*2*...*n, such as 4! =1*2*3*4． Well, 1! +2! +3! +4! +5! = how much.
对于任意自然数，定义n！=1*2*…*n，如4！=1*2*3*4．那么，1！+2！+3！+4！+5！=多少．
<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">1 * 2 * 3</gadget>
<output>6</output>

<gadget id="calculator">1 * 2 * 3 * 4</gadget>
<output>24</output>

<gadget id="calculator">1 * 2 * 3 * 4 * 5</gadget>
<output>120</output>

<gadget id="calculator">1 + 2 + 6 + 24 + 120</gadget>
<output>153</output>

<result>153</result>