import Timer

import Maths

import Data.List

main = do

time match

fourDigitPrimes = filter isPrime [1001..9999]

match :: Integer

match = head [read (aStr ++ bStr ++ cStr) | a <- fourDigitPrimes,

a /= 1487,

b <- dropWhile (<=a) fourDigitPrimes,

let aStr = show a,

let bStr = show b,

let sortaStr = sort aStr,

sortaStr == sort bStr,

let c = 2*b - a,

let cStr = show c,

sortaStr == sort cStr,

isPrime c]