Problem:
Score : 400 points

Problem Statement

Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both voodoo and melee are unbalanced, while neither noon nor a is.

You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.

Constraints

2 ≦ |s| ≦ 10^5

s consists of lowercase letters.

Partial Score

200 points will be awarded for passing the test set satisfying 2 ≦ N ≦ 100.

Input

The input is given from Standard Input in the following format:

s

Output

If there exists no unbalanced substring of s, print -1 -1.

If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print a b. If there exists more than one such substring, any of them will be accepted.

Sample Input 1

needed

Sample Output 1

2 5

The string s_2 s_3 s_4 s_5 = eede is unbalanced. There are also other unbalanced substrings. For example, the output 2 6 will also be accepted.

Sample Input 2

atcoder

Sample Output 2

-1 -1

The string atcoder contains no unbalanced substring.

Solution in Haskell (GHC 7.10.3) (judge verdict: Time Limit Exceeded)

import Control.Applicative
import Control.Monad
import Data.List
import qualified Data.Map.Strict as Map

type I = Int

main :: IO ()
main = do
  xs <- getLine
  putStrLn . (\(a,b) -> show a ++ " " ++ show b) $ solve xs

solve :: String -> (I, I)
solve xs = case find unbalanced $ substrings xs of
  Just x -> case elemIndex True . map (isPrefixOf x) $ tails xs of
    Just i -> (i+1, i + length x)
    Nothing -> (-1, -1)
  Nothing -> (-1, -1)

unbalanced :: String -> Bool
unbalanced xs = length xs > 1 && maxsize xs * 2 > length xs where
  maxsize = maximum . map length . group . sort

substrings :: Eq a => [a] -> [[a]]
substrings = nub . concat . map inits . tails

--  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --

readi :: String -> I
readi = read

toTuple :: [a] -> (a, a)
toTuple [x, y] = (x, y)

toTriple :: [a] -> (a, a, a)
toTriple [x, y, z] = (x, y, z)