According to a coding scheme the sentence Peacock is designated as the national bird of India is coded as $5688999\;35\;1135556678\;56\;458\;13666689\;1334\;79\;13366$
This coding scheme has the following rules:
- The scheme is case-insensitive (does not distinguish between upper case and lower case letters).
- Each letter has a unique code which is a single digit from among $1,2,3,\dots,9$.
- The digit $9$ codes two letters, and every other digit codes there letters.
- The code for a word is constructed by arranging the digits corresponding to its letters in a non decreasing sequence.
Answer these questions on the basis of this information.
For how many digits can the complete list of letters associated with that digit be identified?