output_description: Print the number of ways to paint the string that satisfy the condition.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      S
attempt: 18
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
  
problem_description: Statement
  
  You are given a string S of length 2N consisting of lowercase English letters.
  
  There are 2^{2N} ways to color each character in S red or blue. Among these
  ways, how many satisfy the following condition?
  
    * The string obtained by reading the characters painted red **from left to right** is equal to the string obtained by reading the characters painted blue **from right to left**.
samples: [{"input": "4\n    cabaacba", "output": "4\n    \n\nThere are four ways to paint the string, as follows:\n\n  * cabaacba\n  * cabaacba\n  * cabaacba\n  * cabaacba\n\n* * *"}, {"input": "11\n    mippiisssisssiipsspiim", "output": "504\n    \n\n* * *"}, {"input": "4\n    abcdefgh", "output": "0\n    \n\n* * *"}, {"input": "18\n    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "output": "9075135300\n    \n\nThe answer may not be representable as a 32-bit integer."}]