История изменений

module Main where
import Data.List
test xs ys = xs ++ drop (last $ findIndices (`isSuffixOf` xs) $ inits ys) ys
main = getLine >>= \xs -> getLine >>= \ys -> putStrLn (test xs ys)

[a, b] = 'карусель + сельдь'.split('+').map(e => e.replace(/\s/g, ''));
console.log(a.replace(a.split('').filter((e, i) => b.includes(a.slice(i))).join(''), '').concat(b))

module Main where
import Data.List
test xs ys = xs ++ drop (last $ findIndices (`isSuffixOf` xs) $ inits ys) ys
main = getLine >>= \xs -> getLine >>= \ys -> putStrLn (test xs ys)