use std::io::Read;

fn read<T: std::str::FromStr>() -> T {
    let token: String = std::io::stdin()
        .bytes()
        .map(|c| c.ok().unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().unwrap()
}

fn main() {
    let s: String = read();
    let mut start = -1;
    let mut c = 0;
    let mut w = 0;
    for (i, &x) in s.chars().collect::<Vec<_>>().iter().enumerate() {
        if x == 'c' {
            c += 1;
            start = i as i32;
        }
        if x == 'w' && c >= 1 {
            w += 1;
        }
        if c >= 1 && w >= 2 {
            println!("{}", i as i32 - start + 1);
            return;
        }
    }
    println!("-1");
}