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: # -*- coding: utf-8 -*-
  
  
  def f(k, a, b):
      if b - a <= 0:
          return k + 1
      elif k + 1 < a:
          return k + 1
      else:
          res1 = k + 1
          res2 = b
          k -= 1 + a
          # print(k,res2)
          if k > 0:
              res2 += (b - a) * (k // 2)
              res2 += k % 2
          elif k < 0:
              res2 = -1
          return max(res1, res2)
  
  
  def f2(k, a, b):
      k_ = k
      res = 1
      while k > 0 and res < a:
          res += 1
          k -= 1
      res += (b - a) * (k // 2)
      res += k % 2
      return max(res, k_ + 1)
  
  
  if __name__ == "__main__":
      k, a, b = map(int, input().split())
      print(f(k, a, b))
  
      # print(f(3,3,5))
      # from random import randint
      # for _ in range(1000):
      #     k = randint(1,100)
      #     a = randint(1,100)
      #     b = randint(1,100)
      #     res1 = f(k,a,b)
      #     res2 = f2(k,a,b)
      #     if res1!=res2:
      #         print(k,a,b)
      #         print(res1,res2)
      #         break
  
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"}]