use std::{
    collections::{BTreeSet, HashMap},
    hash::Hash,
};

fn main() {
    proconio::input! {
        s: String,
    }
    let mut cww_max = i64::MAX;
    let s = s.chars().collect::<Vec<_>>();
    for (i_c, _) in s.iter().copied().enumerate().filter(|c| c.1 == 'c') {
        if let Some((i_w1, _)) = s
            .iter()
            .copied()
            .enumerate()
            .skip(i_c + 1)
            .find(|c| c.1 == 'w')
        {
            if let Some((i_w2, _)) = s
                .iter()
                .copied()
                .enumerate()
                .skip(i_w1 + 1)
                .find(|c| c.1 == 'w')
            {
                cww_max = std::cmp::min(cww_max, (i_w2 - i_c) as i64 + 1);
            }
        }
    }
    println!("{}", if cww_max == i64::MAX { -1 } else { cww_max });
}