digit :: Int -> Int -> Int
nth `digit` n = n `mod` 10 ^ nth `div` 10 ^ (nth - 1)

feinman :: [(Int, Int)]
feinman = [ (n1, n2)
          | b <- [1..9], a <- [0..9], c <- [0..9],
            d <- [1..9], e <- [0..9], f <- [0..9],
            a /= b, a /= c, a /= d, a /= e, a /= f, e < d,
            let n1 = 100 * b + 10 * a + c,
            let n2 = 1000 * d + 100 * e + 10 * a + f,
            n1 * n2 > 999999, n1 * n2 < 10000000,
            digit 3 (n1 * n2) == a,
            digit 1 (d * n1) == a, digit 2 (d * n1) == a,
            digit 1 (e * n1) == a, digit 3 (a * n1) == a]

main :: IO ()
main = print feinman