import Data.Array.ST
import Control.Monad.ST
import Data.List
import Data.Maybe

solve :: Int -> [(Int,Int)] -> Int
solve n xs = runST $ do
    a <- newListArray (1,3) [0,0,0] :: ST s (STArray s Int Int)
    writeArray a n 1
    go a xs
    succ . fromJust . elemIndex 1 <$> getElems a 
  where
    go a [] = return ()
    go a ((i,j):xs) = do
        x <- readArray a i
        y <- readArray a j
        writeArray a i y
        writeArray a j x

main :: IO ()
main = do
    n <- readLn :: IO Int
    m <- readLn :: IO Int
    pq <- map ((\[a,b] -> (a,b)) . (map read . words))
        . lines <$> getContents :: IO [(Int,Int)]
    print $ solve n pq