According to the text, there are always keys from a letter name to its next occurrence up or down the keyboard.

8 (eight)

Explanation:

A piano keyboard is a musical instrument, with tabs of white and black keys that makes sound ranging from a low pitch to a high pitch sound. Its keys a labelled from A to G and occur several times on the keyboard.

If a letter "C" is pressed on the keyboard, a count of eight keys gives another occurrence of "C" again, whether it is counted upwards or downwards , but it gives a slightly higher pitch than the former "C".