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


fn main() {
    let mut temp = String::new();
    std::io::stdin().read_line(&mut temp).ok();
    let temp: Vec<&str> = temp.trim().split_whitespace().collect();

    let tset = temp.iter().copied().collect::<BTreeSet<_>>();
    let mut mapping = HashMap::new();
    for (i, &v) in tset.iter().enumerate() {
        mapping.insert(v, i);
    }
    let a = (0..6).map(|i| *mapping.get(&temp[i]).unwrap()).collect::<Vec<usize>>();
    for i in 0..1<<tset.len() {
        let flgs = (0..6).map(|j| ((i >> a[j]) & 1) == 1).collect::<Vec<bool>>();
        if !(!(!(flgs[0] && flgs[1]) && flgs[2]) && !(!(flgs[3] && flgs[4]) && flgs[5])) {
            println!("YES");
            return;
        }
    }
    println!("NO");
}