Some natural numbers can be expressed in the form of multiplying two composite numbers and adding a composite number, for example: 33=4*6+9. May I ask: What is the largest natural number that cannot be represented in this form?
有些自然数可以表示成两个合数相乘再加一个合数的形式，例如：33=4*6+9．请问：不能表示成这种形式的自然数最大是多少？
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">16 + 27</gadget>
<output>43</output>

<gadget id="calculator">43 - 8</gadget>
<output>35</output>

<result>35</result>