Problem Statement  
John and Brus are studying string theory at the university. Their task is to create a list of all the palindromes that contain between 1 and n lowercase letters ('a''z'), inclusive. A palindrome is a string that reads the same forward and backward. Additionally, each palindrome in their list must contain no more than k distinct letters. Return the number of palindromes in the list modulo 1234567891.  
Definition  
 
Constraints  
  n will be between 1 and 1,000,000,000, inclusive.  
  k will be between 1 and 26, inclusive.  
Examples  
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