module Main where

main :: IO ()
main = getIntList >>= print . solve

solve :: [Int] -> Int
solve [a, b] = let (hA, mA) = calcAngles a b
                   dist = modf (hA + 360.0 - mA) 360.0
               in  floor $ dist / (6.0 - 0.5) * 60

calcAngles :: Int -> Int -> (Double, Double)
calcAngles h m = let mA = (fromIntegral m) * 6.0
                     h' = fromIntegral $ h `mod` 12
                     hA = h' * 30.0 + (fromIntegral m) * 0.5
                 in  (hA, mA)

modf :: Double -> Double -> Double
modf a b | a >= b    = modf (a - b) b
         | otherwise = a

getIntList :: IO [Int]
getIntList = map read . words <$> getLine