It is known that A and B are both natural numbers, A*B=72, then how much is the largest A+B.
已知A、B都是自然数，A*B=72，那么A+B最大得多少．
<gadget id="calculator">1 * 72</gadget>
<output>72</output>

<gadget id="calculator">1 + 72</gadget>
<output>73</output>

<result>73</result>