import Control.Applicative
import Control.Monad
import Control.Monad.ST
-- import qualified Data.ByteString as BS
import Data.Functor
import Data.Function
import Data.Monoid
import Data.Maybe
import Data.List
import qualified Data.Foldable as Foldable
import qualified Data.Set as Set
--import qualified Data.Sequence as Sequence
import Data.List.Split
import Data.Bits
import Data.Char
import Data.Ix
import Data.Ratio
import Data.Ord
import Data.Tuple
import Data.Array
--import Data.Array.Unboxed
--import Data.Array.IArray
import Data.Array.MArray
import Data.Array.IO
import Data.Array.ST
import Data.IORef
import Data.STRef
import GHC.ST
-- import System.IO.Unsafe
 
-- templete
readInt = read :: String -> Int
readInteger = read :: String -> Integer
readDouble = read :: String -> Double
getInt = readLn :: IO Int
getInts = map readInt . words <$> getLine
getInteger = readLn :: IO Integer
getIntegers = map readInteger . words <$> getLine
getDouble = readLn :: IO Double
getDoubles = map readDouble . words <$> getLine
sjoin :: (Show a) => [a] -> String
sjoin = unwords . map show
tjoin :: (Show a, Show b) => (a, b) -> String
tjoin (x, y) = show x ++ (' ' : show y)
cond :: a -> a -> Bool -> a
cond t f c = if c then t else f
apply2 :: (a -> a -> b) -> [a] -> b
apply2 f [x,y] = f x y
apply3 :: (a -> a -> a -> b) -> [a] -> b
apply3 f [x,y,z] = f x y z
apply4 :: (a -> a -> a -> a -> b) -> [a] -> b
apply4 f [x,y,z,w] = f x y z w
fnTuple :: (a -> b, a -> c) -> a -> (b, c)
fnTuple (f,g) a = (f a, g a)
replace :: (Eq a) => a -> a -> [a] -> [a]
replace x y = map (\z -> if z==x then y else z)
binMap :: (a -> a -> b) -> [a] -> [b]
binMap f (x:xs@(y:_)) = f x y : binMap f xs
binMap _ _ = []
splitRec :: Int -> [a] -> [[a]]
splitRec _ [] = []
splitRec n xs = let (y,ys) = splitAt n xs in y : splitRec n ys
infixl 7 `divCeil`
divCeil :: Integral a => a -> a -> a
x `divCeil` y = (x+y-1) `div` y
coverC :: Ord a => (a, a) -> a -> Bool
coverC (l,r) x = l<=x && x<=r
coverH :: Ord a => (a, a) -> a -> Bool
coverH (l,r) x = l<=x && x<r
ibsearch :: (Int -> Bool) -> (Int,Int) -> Int
ibsearch f (ok,ng) = if abs (ok-ng) <= 1 then ok else let mid = (ok + ng) `div` 2 in ibsearch f (if f mid then (mid,ng) else (ok,mid))
whenM :: Monad m => m Bool -> m () -> m ()
whenM c a = c >>= flip when a
-- templete

data Visited = Yet | Temp Int | Perm deriving (Show, Eq)

f :: Int -> [Int] -> Int
f n as = runST $ do
    let next = listArray (0,n-1) $ zipWith (((`mod`n) .) . (+)) [0..n-1] as :: Array Int Int
    visited <- newArray (0,n-1) Yet :: ST s (STArray s Int Visited)
    sum <$> sequence [search next visited i i 1 | i <- [0..n-1]]
  where
    visitPerm :: Array Int Int -> STArray s Int Visited -> Int -> ST s ()
    visitPerm next visited x = do
        state <- readArray visited x
        case state of
            Temp _ -> writeArray visited x Perm >> visitPerm next visited (next!x)
            _ -> return ()
    search next visited ix x i = do
        state <- readArray visited x
        case state of
            Yet -> writeArray visited x (Temp i) >> search next visited ix (next!x) (i+1)
            Temp j -> do
                let res = i-j
                visitPerm next visited ix
                return res
            Perm -> visitPerm next visited ix >> return 0


main = do
    f <$> getInt <*> getInts >>= print



Measured memory_bytes: 94280