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;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class GFG
{
    static public void Main()
    {
        try
        {
            var n = Console.ReadLine();
            //var input1 = Console.ReadLine().Split(' ');
            //var n = int.Parse(input1[0]);
            //var L = int.Parse(input1[1]);

            //var aar = Console.ReadLine().Split(' ').Select(x => Int32.Parse(x)).ToArray();

            SubString(n);
        }
        catch (Exception ex)
        {
            Console.Write(ex);
        }
    }

    static void SubString(string s)
    {

        for (int i = 2; i < s.Length; i++)
        {
            if ((s[i - 2] == s[i]) && (s[i - 2] != s[i - 1]) && (s[i] != s[i - 1]))
            {
                Console.Write((i - 2 + 1) + " " + (i + 1));
            }
        }

        Console.Write("-1 -1");

    }

    static bool UnBal(string s)
    {
        if (s.Length <= 1)
            return false;

        var ss = s.ToCharArray();
        int n = ss.Length;
        var group = ss.GroupBy(x => x).Select(g => new { l = g.Key, count = g.Count() });

        foreach (var cc in group)
        {
            if (cc.count > (n / 2))
                return true;
        }
        return false;

    }

}