output_description: Print the maximum possible number of biscuits in Snuke's pocket after K
  operations.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      K A B
attempt: k, a, b = map(int, input().split())
  i = a - 1
  c = a
  j = k - i
  c += b * (j // 2)
  c -= a * (j // 2)
  print(max(k + 1, c + j % 2))
  
problem_description: Statement
  
  Snuke has one biscuit and zero Japanese yen (the currency) in his pocket. He
  will perform the following operations exactly K times in total, in the order
  he likes:
  
    * Hit his pocket, which magically increases the number of biscuits by one.
    * Exchange A biscuits to 1 yen.
    * Exchange 1 yen to B biscuits.
  
  Find the maximum possible number of biscuits in Snuke's pocket after K
  operations.
samples: [{"input": "4 2 6", "output": "7\n    \n\nThe number of biscuits in Snuke's pocket after K operations is maximized as\nfollows:\n\n  * Hit his pocket. Now he has 2 biscuits and 0 yen.\n  * Exchange 2 biscuits to 1 yen. his pocket. Now he has 0 biscuits and 1 yen.\n  * Hit his pocket. Now he has 1 biscuits and 1 yen.\n  * Exchange 1 yen to 6 biscuits. his pocket. Now he has 7 biscuits and 0 yen.\n\n* * *"}, {"input": "7 3 4", "output": "8\n    \n\n* * *"}, {"input": "314159265 35897932 384626433", "output": "48518828981938099"}]