The sum of the digits of a natural number is 5 (for example: the sum of the digits of 13 is 1+3=4, the sum of the digits of 7 is 7), and the digits of each digit are different. How many such natural numbers are there?
一个自然数各位上的数字之和是5(例如：13的数字和为1+3=4，7的数字之和为7)，而且各位数字都不相同．这样的自然数有多少个．
<gadget id="calculator">1 + 2 + 2 + 4 + 4 + 1</gadget>
<output>14</output>

<result>14</result>