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

solve k a b
  | 2 >= b - a =
      1 + k
  | otherwise =
      let x = 0 `max` ((k - (a - 1)) `div` 2) in
      if x > 0 then a + (b - a) * x + k - (a - 1 + 2 * x)
      else 1 + k