solve k a b
  | b - a < 2 = k + 1
  | k' == 0 = 1 + a'
  | otherwise = 1 + a' + cnt * (b-a) + m
    where
      a' = min k (a-1)
      k' = k - a'
      cnt = k' `div` 2
      m = k' `mod` 2

main = do
  [k,a,b] <- map read . words <$> getLine :: IO [Int]
  print $ solve k a b
