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

public class Don
{
    public Don() { }
    private Reader r = new Reader();

    public void Solve()
    {
        var S = r.next();
        var abc = "abcdefghijklmnopqrstuvwxyz";
        var max = 0;
        var maxalpha = ' ';
        var counts = new List<int>();
        for(var i = 0; i < abc.Length; i++)
        {
            counts.Add(S.Count(x => x == abc[i]));
            if (S.Count(x => x == abc[i]) > max)
            {
                max = S.Count(x => x == abc[i]);
                maxalpha = abc[i];
            }
        }
        if(counts.Count(x => x == max) != 1)
        {
            Console.WriteLine("-1 -1");
            return;
        }
        var start = S.Length;
        var end = 0;
        for(var i = 0; i < S.Length; i++)
        {
            if (S[i] == maxalpha)
            {
                start = Math.Min(i + 1, start);
                max--;
                if (max == 0)
                {
                    end = i + 1;
                }
            }
        }
        Console.WriteLine("{0} {1}", start, end);
    }

    public static void Main(string[] args)
    {
        new Don().Solve();
    }

}

class Reader
{
    string[] s;
    int i;
    char[] cs = new char[] { ' ' };

    public Reader()
    {
        s = new string[0];
        i = 0;
    }

    public string next()
    {
        if (i < s.Length)
            return s[i++];
        var input = Console.ReadLine();
        while (input == "")
            input = Console.ReadLine();
        s = input.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        i = 0;
        return next();
    }

    public int nextInt()
    {
        return int.Parse(next());
    }

    public long nextLong()
    {
        return long.Parse(next());
    }

    public double nextDouble()
    {
        return double.Parse(next());
    }

}