import Data.Ratio

f :: [Integer] -> [Ratio Integer]
f (x:y:[]) = [y % x]
f (x:y:xs) = y % x : f (y:xs)

main = do
	getLine
	z <- return . product . f . map read . words =<< getLine
	putStrLn $ show (numerator z) ++ "/" ++ show (denominator z)