import Data.Maybe

main = do
  _ <- getLine
  s <- getLine

  putStrLn $ h (catMaybes [g a b s | a<-"SW", b<-"SW"])
  
  where
    h [] = "-1"
    h a = head a
    g a b xs = if b == rl then Just ri else Nothing
      where
        r = f a b xs
        ri = init r
        rl = last r
    f _ b [] = [b]
    f a b (x:xs)
      | a == 'S' && b == 'S' =
        if x == 'o' then
          b : (f b 'S' xs)
        else
          b : (f b 'W' xs)
      | a == 'W' && b == 'S' =
        if x == 'o' then
          b : (f b 'W' xs)
        else
          b : (f b 'S' xs)
      | a == 'S' && b == 'W' =
        if x == 'o' then
          b : (f b 'W' xs)
        else
          b : (f b 'S' xs)
      | a == 'W' && b == 'W' =
        if x == 'o' then
          b : (f b 'S' xs)
        else
          b : (f b 'W' xs)