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: Wrong Answer)

use std::io;
use std::str::FromStr;
use std::str::Chars;
use std::i32;
use std::u8;
use std::f64;
use std::ascii::AsciiExt;
use std::collections::HashMap;
use std::collections::HashSet;
use std::collections::BTreeMap;
use std::collections::BTreeSet;
use std::collections::VecDeque;
use std::io::prelude::*;
use std::time::Duration;
use std::cmp;

macro_rules! println_stderr(
    ($($arg:tt)*) => { {
        let r = writeln!(&mut ::std::io::stderr(), $($arg)*);
        r.expect("failed printing to stderr");
    } }
);

macro_rules! print_stderr(
    ($($arg:tt)*) => { {
        let r = write!(&mut ::std::io::stderr(), $($arg)*);
        r.expect("failed printing to stderr");
    } }
);

fn main() {
    let s = next_string();
    let mut i = 0;
    let mut prev = 'z' as u8 + 1;
    for c in s.bytes() {
        if prev == c {
            println!("{} {}", i, i + 1);
            return;
        }
        prev = c;
        i += 1;
    }
    println!("-1 -1");
}

#[allow(dead_code)]
fn next_string() -> String {
    let mut input = String::new();
    io::stdin().read_line(&mut input).unwrap();
    input
}

#[allow(dead_code)]
fn next_strings() -> Vec<String> {
    let input = next_string();
    input.split_whitespace().map(|x| x.parse().unwrap()).collect()
}

#[allow(dead_code)]
fn next_int() -> i64 {
    let input = next_string();
    i64::from_str(input.trim()).unwrap()
}

#[allow(dead_code)]
fn next_ints() -> Vec<i64> {
    let input = next_string();
    input.split_whitespace().map(|x| x.parse().unwrap()).collect()
}