Each symbol in the Braille code is represented by a rectangular arrangement of six dots, each of which may be raised or flat against a smooth background. For instance, when the word Braille is spelled out, it looks like this:
![2453_c6db9a3a-e6ab-41c3-ada4-23d478acaf92.png](https://secure.tutorsglobe.com/CMSImages/2453_c6db9a3a-e6ab-41c3-ada4-23d478acaf92.png)
Given that at least one of the six dots must be raised, how many symbols can be represented in the Braille code?