import Control.Applicative
main = do (a:b:c:_) <- map read . lines <$> getContents
          let d = lcm (lcm a b) c :: Integer
              e = f (d`div`a) (d`div`b) (d`div`c) (d`div`a)
          putStrLn $ (show d) ++ '/':show e
f a b c d | (a `mod` d) == (b `mod` d) && (b `mod` d) == (c `mod` d) = d
          | d <= 1 = 1
          | otherwise = f a b c (d-1)