Problem Statement  
Tom is a little boy who likes to collect toys. On his birthday, his mom bought him a box of toy soldiers as a gift. There are n soldiers in the box, labeled 1 to n on their uniforms. The numbers are written with no leading zeroes. Tom starts counting the soldiers, but he soon finds that it's difficult to count them all. He decides to count only the soldiers with labels that have length between lowerBound and upperBound, inclusive. Return the number of soldiers that Tom will count.  
Definition  
 
Constraints  
  n will be between 1 and 10,000,000, inclusive.  
  lowerBound will be between 1 and 8, inclusive.  
  upperBound will be between lowerBound and 8, inclusive.  
Examples  
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