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 Ruby (2.3.3) (judge verdict: Wrong Answer)

def subset(list, head, tail)

  if tail > list.length then
    return nil
  end

  border = ((tail - head + 1).to_f / 2)
  isUnbalanced = list[head..tail].reduce(Hash.new(0)) {|memo, k| memo[k] += 1; memo;}.any?{|k, v| v > border}

  if isUnbalanced then
    return sprintf('%d %d', head, tail)
  end

  if tail - head > 1 then
      result = subset(list, head + 1, tail)
  end

  if result.nil? then
    return subset(list, head, tail + 1)
  else
    return result
  end
end

s = gets.chomp.split('')
result = subset(s, 0, 1)

puts result.nil? ? '-1 -1' : result