Choose 6 numbers from the prime numbers within 20, and write these 6 numbers on the six faces of a cube, so that the sum of the numbers on every two opposite faces of the cube is equal. So, what is the sum of these 6 numbers?
从20以内的质数中选出6个数，将这6个数写在一个正方体木块的六个面上，使正方体中每两个相对面上的数之和都相等．那么，这6个数连加的和是多少．
<gadget id="calculator">5 + 7 + 11 + 13 + 17 + 19</gadget>
<output>72</output>

<result>72</result>