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 Rust (1.15.1) (judge verdict: Accepted)

use std::io;
use std::cmp;
use std::collections::BinaryHeap;
use std::collections::HashMap;
use std::collections::HashSet;
use std::f64::consts::PI;

fn read_line() -> String {
    let mut buf = String::new();
    io::stdin().read_line(&mut buf).ok();
    buf
}


fn main() {
    let line = read_line();
    let s: Vec<char> = line.trim().chars().collect();
    let n = s.len();
    let mut ans = None;
    for i in 0..26 {
        let tar = ('a' as u8 + i) as char;
        let mut count = -1;
        let mut pos = 0;
        let mut l = 0;
        while pos < n {
            if s[pos] == tar {
                if count < 0 {
                    l = pos;
                    count = 0;
                }
                count += 1;
                if pos-l >= 1 && count > 0 {
                    ans = Some((l+1, pos + 1));
                    break;
                }
            } else {
                count -= 1;
            }
            pos += 1;
        }
    }
    if let Some((l, r)) = ans {
        println!("{} {}", l, r);
    } else {
        println!("-1 -1");
    }
}