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;

fn unbalanced_index(string: &String) -> Option<(usize, usize)> {
    let s = string.as_bytes();
    // println!("'{}': len = {}", string, s.len());
    for i in 0..(s.len() - 1) {
        // println!("'{}': i = {}", string, i);
        if s[i] == s[i + 1] {
            // println!("'{}': aa", string);
            return Some((i, i + 1));
        }
        if s.len() - 3 < i {
            // println!("'{}': eos", string);
            return None;
        }
        if s[i] == s[i + 2] {
            // println!("'{}': aXa", string);
            return Some((i, i + 2));
        }
    }
    return None;
}

fn is_unbalanced(s: &String) -> bool {
    match unbalanced_index(s) {
        Some((_, _)) => true,
        None => false,
    }
}

#[test]
fn test_is_unbalanced() {
    assert!(is_unbalanced(&"needed".to_string()));
    assert!(!is_unbalanced(&"atcoder".to_string()));
}

fn main() {
    let mut input = String::with_capacity(10002);
    io::stdin().read_line(&mut input).unwrap();
    match unbalanced_index(&input) {
        Some((a, b)) => println!("{} {}", a + 1, b + 1),
        None => println!("-1 -1"),
    }
}