import Data.IntMap.Strict ((!))
import qualified Data.IntMap.Strict as M
import qualified Data.Set as S
import qualified Data.ByteString.Char8 as B
import Control.Monad
import Data.Maybe
import Data.List

type Cost = Int
type Vertex = Int

type Heap = S.Set (Cost, Vertex)
nullq = S.null
empty = S.empty 
push c v = S.insert (c,v)
pop = S.deleteFindMin

main = do
 [n,_,s,g] <- map read . words <$> getLine
 es <- map (map (fst . fromJust . B.readInt) . B.words) . B.lines <$> B.getContents
 putStrLn $ unwords $ map show (route n s g es)

route n s g es = unfoldr (backtrack imr) s ++ [g]
 where 
  imr = dijkstra t im0 q0
  t = foldl' (\acc [a,b,c] -> M.insertWith (++) b [(a,c)] (M.insertWith (++) a [(b,c)] acc)) M.empty es
  im0 = M.singleton g (0,[])
  q0 = push 0 g empty

backtrack im v = case im!v of
 (0,[]) -> Nothing
 (_,(vp:_)) -> Just (v,vp)

dijkstra t im q
 | nullq q = im
 | otherwise = dijkstra t im' q''
 where
  ((c0,v),q') = pop q
  im' = foldl' (\acc (b,c) -> M.insertWith mindic b (c0+c,[v]) acc) im vns
  q'' = foldl' (\acc (b,c) -> push (c0+c) b acc) q' vns
  vns = filter (\(b,c) -> M.notMember b im || c0+c <= fst (im!b)) (M.findWithDefault [] v t)

mindic (c1,v1@[v]) (c2,v2)
 | c1 < c2 = (c1,v1)
 | c1 == c2 = (c1, insert v v2)