import Data.Set (fromList, toAscList)

findMinimumDistance :: [Int] -> Int
findMinimumDistance [] = 0
findMinimumDistance (_ : []) = 0
findMinimumDistance (a : b : []) = b - a
findMinimumDistance (a : b : xs) = min (b - a) $ findMinimumDistance (b : xs)

main :: IO ()
main = print . findMinimumDistance . toAscList. fromList . map read . words . head . drop 1 . lines =<< getContents