use proconio::input;

fn main() {
    input! {
    n: usize,
    s: String,
    }
    let cs = s.chars().collect::<Vec<_>>();
    let mut f = false;
    let mut ans = vec![];
    for (i, c) in cs.into_iter().enumerate() {
        if c == 'o' {
            if !f {
                ans.push(i + 1);
            }
            f = true;
        } else {
            f = false;
        }
    }

    let m = ans.len();
    println!("{m}");
    for (i, a) in ans.into_iter().enumerate() {
        print!("{a}");
        if i < m {
            print!(" ");
        }
    }
    println!();
}