output_description: Print the number of strings satisfying the condition, modulo (10^9+7).
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      K
      S
attempt: def main():
    k = int(input())
    s = input()
    n = 1
    for i in range( len(s)-1, k+1):
      n = n * i
    
  if __name__ == '__main__':
    main()
problem_description: Statement
  
  How many strings can be obtained by applying the following operation on a
  string S exactly K times: "choose one lowercase English letter and insert it
  somewhere"?
  
  The answer can be enormous, so print it modulo (10^9+7).
samples: [{"input": "5\n    oof", "output": "575111451\n    \n\nFor example, we can obtain `proofend`, `moonwolf`, and `onionpuf`, while we\ncannot obtain `oofsix`, `oofelevennn`, `voxafolt`, or `fooooooo`.\n\n* * *"}, {"input": "37564\n    whydidyoudesertme", "output": "318008117"}]