use itertools::Itertools;
use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        a: [usize; 13],
    }
    let mut ans = Vec::new();
    for x in 1..=9 {
        let mut v = vec![0; 10];
        v[x] += 1;
        for &ai in &a {
            v[ai] += 1;
        }

        let mut cnt_three = 0;
        let mut cnt_two = 0;
        for &vi in &v {
            if vi == 3 {
                cnt_three += 1;
            } else if vi == 2 {
                cnt_two += 1;
            }
        }

        if (cnt_three == 4) && (cnt_two == 1) {
            ans.push(x);
        }
    }

    println!("{}\n{}", ans.len(), ans.iter().format(" "));
}