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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;

class Unbalanced
{
	static void Main(String[] args)
	{
		String S = Console.ReadLine();
		int length = S.Length;
		int[,] counts = new int[length+1,26];

		for(int i=0; i<length; i++)
		{
			counts[i+1,S[i]-'a'] = counts[i,S[i]-'a'] + 1;
		}
		for(int i=0; i<length-1; i++)
		{
			for(int j=i+1; j<length; j++)
			{
				int thresh = (j-i+1)/2;
				for(char c='a'; c<='z'; c++)
				{
					int count=counts[j+1,c-'a'] - counts[i+1-1, c-'a'];
					if(count > thresh)
					{
						Console.WriteLine("{0} {1}", i+1, j+1);
						return;
					}
				}
			}
		}
		Console.WriteLine("-1 -1");
	}
}