{-# LANGUAGE ScopedTypeVariables #-}
import Data.List

main = do
    lines <- readFile "3.in"
    putStrLn . show . solve . (!!0) . words $ lines
    where
        solve = length . Data.List.group . Data.List.sort . partB

-- solves all lines, returns a string
partA :: [Char] -> [(Int, Int)]
partA = getPositions
    where
        getPositions = snd . foldl updatePosition ((0,0), [(0,0)]) . map coords
        -- updatePosition :: b -> a -> b
        updatePosition ((x, y), positions) (a, b) = ((x + a, y + b), (x + a, y + b):positions)
        -- (right, up)
        coords '>' = (1, 0)
        coords '<' = (-1, 0)
        coords 'v' = (0, -1)
        coords '^' = (0, 1)
        coords  _  = (0, 0)

partB :: [Char] -> [(Int, Int)]
partB l = id =<< [ partA . odds $ l, partA . evens $ l]
    where
        evens = odds . tail
        odds [] = []
        odds [x] = [x]
        odds (x:y:r) = x:(odds r)