If MSD is 4. For example if n = 428 , then count of numbers is sum of following . 1 ) Count of numbers from 1 to 399 2 ) Count of numbers from 400 to 428 which is 29.
if ( msd == 4 ) : NEW_LINE INDENT return ( msd ) * a [ d ] + ( n % p ) + 1 NEW_LINE DEDENT