import System.IO

doStep (0, valleys) 'D' = (-1, valleys+1)
doStep (level, valleys) 'D' = (level-1, valleys)
doStep (level, valleys) 'U' = (level+1, valleys)

countValleys :: [Char] -> Integer
countValleys steps = snd $ foldl doStep (0, 0) steps

main = do
	l0 <- getLine
	l1 <- getLine
	let 
		n = read l0
		steps = take n l1
	putStrLn $ show $ countValleys steps