#![allow(dead_code, unused_variables, unused_macros)]
// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, bits)=>{
        u64::from_str_radix(&$next(), 2).expect("Parse error")
    };

    ($next:expr, hexs)=>{
        u64::from_str_radix(&$next(), 16).expect("Parse error")
    };


    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

fn solve(s: String) -> i32 {
    let c_list: Vec<_> = s
        .chars()
        .enumerate()
        .filter_map(|(i, c)| (c == 'c').then_some(i))
        .collect();
    let w_list: Vec<_> = s
        .chars()
        .enumerate()
        .filter_map(|(i, c)| (c == 'w').then_some(i))
        .collect();
    let mut min_len = i32::MAX;
    for ci in c_list {
        if let Some(w2_index) = w_list.iter().filter(|&&i| ci < i).nth(1) {
            min_len = min_len.min((w2_index - ci + 1) as i32);
        }
    }
    if min_len == i32::MAX {
        -1
    } else {
        min_len
    }
}

fn main() {
    input!(s:String);
    println!("{}", solve(s));
}