#[allow(unused_imports)]
use std::io::{stdout, BufWriter, Write};

use std::hash::{Hash, Hasher};

fn nand(a: bool, b: bool) -> bool {
    !(a & b)
}

fn main() {
    let out = stdout();
    let mut out = BufWriter::new(out.lock());

    let mut v = input_vector::<String>();
    let mut w = vec![];

    for i in v {
        let mut hasher = std::collections::hash_map::DefaultHasher::new();
        i.hash(&mut hasher);
        w.push(hasher.finish());
    }

    seq_compress(&mut w, 0, 1);

    for i in 0_i64..1 << 5 {
        let a = (i >> w[0]) & 1 == 1;
        let b = (i >> w[1]) & 1 == 1;
        let c = (i >> w[2]) & 1 == 1;
        let d = (i >> w[3]) & 1 == 1;
        let e = (i >> w[4]) & 1 == 1;
        let f = (i >> w[5]) & 1 == 1;

        if nand(nand(nand(a, b), c), nand(nand(d, e), f)) {
            writeln!(out, "YES").unwrap();
            return;
        }
    }
    writeln!(out, "NO").unwrap();
}

//https://github.com/manta1130/competitive-template-rs

use input::*;
use vectools::*;

pub mod input {
    use std::cell::RefCell;
    use std::io;
    pub const SPLIT_DELIMITER: char = ' ';
    pub use std::io::prelude::*;

    thread_local! {
        pub static INPUT_BUFFER:RefCell<std::collections::VecDeque<String>>=RefCell::new(std::collections::VecDeque::new());
    }

    #[macro_export]
    macro_rules! input_internal {
        ($x:ident : $t:ty) => {
            INPUT_BUFFER.with(|p| {
                while p.borrow().len() == 0 {
                    let temp_str = input_line_str();
                    let mut split_result_iter = temp_str
                        .split(SPLIT_DELIMITER)
                        .map(|q| q.to_string())
                        .filter(|q| q.len() > 0)
                        .collect::<std::collections::VecDeque<_>>();
                    p.borrow_mut().append(&mut split_result_iter)
                }
            });
            let mut buf_split_result = String::new();
            INPUT_BUFFER.with(|p| buf_split_result = p.borrow_mut().pop_front().unwrap());
            let $x: $t = buf_split_result.parse().unwrap();
        };
        (mut $x:ident : $t:ty) => {
            INPUT_BUFFER.with(|p| {
                while p.borrow().len() == 0 {
                    let temp_str = input_line_str();
                    let mut split_result_iter = temp_str
                        .split(SPLIT_DELIMITER)
                        .map(|q| q.to_string())
                        .filter(|q| q.len() > 0)
                        .collect::<std::collections::VecDeque<_>>();
                    p.borrow_mut().append(&mut split_result_iter)
                }
            });
            let mut buf_split_result = String::new();
            INPUT_BUFFER.with(|p| buf_split_result = p.borrow_mut().pop_front().unwrap());
            let mut $x: $t = buf_split_result.parse().unwrap();
        };
    }

    pub fn input_buffer_is_empty() -> bool {
        let mut empty = false;
        INPUT_BUFFER.with(|p| {
            if p.borrow().len() == 0 {
                empty = true;
            }
        });
        empty
    }

    #[macro_export]
    macro_rules! inputv {
    ($i:ident : $t:ty) => {
        input_internal!{$i : $t}
    };
    (mut $i:ident : $t:ty) => {
        input_internal!{mut $i : $t}
    };
    ($i:ident : $t:ty $(,)*) => {
            input_internal!{$i : $t}
    };
    (mut $i:ident : $t:ty $(,)*) => {
            input_internal!{mut $i : $t}
    };
    (mut $i:ident : $t:ty,$($q:tt)*) => {
            input_internal!{mut $i : $t}
            inputv!{$($q)*}
    };
    ($i:ident : $t:ty,$($q:tt)*) => {
            input_internal!{$i : $t}
            inputv!{$($q)*}
    };
}

    pub fn input_all() {
        INPUT_BUFFER.with(|p| {
            if p.borrow().len() == 0 {
                let mut temp_str = String::new();
                std::io::stdin().read_to_string(&mut temp_str).unwrap();
                let mut split_result_iter = temp_str
                    .split_whitespace()
                    .map(|q| q.to_string())
                    .collect::<std::collections::VecDeque<_>>();
                p.borrow_mut().append(&mut split_result_iter)
            }
        });
    }

    pub fn input_line_str() -> String {
        let mut s = String::new();
        io::stdin().read_line(&mut s).unwrap();
        s.trim().to_string()
    }

    #[allow(clippy::match_wild_err_arm)]
    pub fn input_vector<T>() -> Vec<T>
    where
        T: std::str::FromStr,
    {
        let mut v: Vec<T> = Vec::new();

        let s = input_line_str();
        if s.is_empty() {
            return v;
        }
        let split_result = s.split(SPLIT_DELIMITER);
        for z in split_result {
            let buf = match z.parse() {
                Ok(r) => r,
                Err(_) => panic!("Parse Error",),
            };
            v.push(buf);
        }
        v
    }

    #[allow(clippy::match_wild_err_arm)]
    pub fn input_vector_row<T>(n: usize) -> Vec<T>
    where
        T: std::str::FromStr,
    {
        let mut v = Vec::with_capacity(n);
        for _ in 0..n {
            let buf = match input_line_str().parse() {
                Ok(r) => r,
                Err(_) => panic!("Parse Error",),
            };
            v.push(buf);
        }
        v
    }

    pub trait ToCharVec {
        fn to_charvec(&self) -> Vec<char>;
    }

    impl ToCharVec for String {
        fn to_charvec(&self) -> Vec<char> {
            self.to_string().chars().collect::<Vec<_>>()
        }
    }
}
pub mod vectools {
    pub trait BSearch<T>
    where
        T: PartialOrd,
    {
        fn lower_bound(&self, k: T) -> usize;
        fn upper_bound(&self, k: T) -> usize;
    }

    impl<T> BSearch<T> for Vec<T>
    where
        T: PartialOrd,
    {
        fn lower_bound(&self, k: T) -> usize {
            let mut from = 0;
            let mut to = self.len();
            while to - from > 1 {
                let mid = (from + to) / 2;
                if self[mid] < k {
                    from = mid;
                } else {
                    to = mid;
                }
            }
            if self[from] < k {
                to
            } else {
                from
            }
        }
        fn upper_bound(&self, k: T) -> usize {
            let mut from = 0;
            let mut to = self.len();
            while to - from > 1 {
                let mid = (from + to) / 2;
                if self[mid] <= k {
                    from = mid;
                } else {
                    to = mid;
                }
            }
            if self[from] > k {
                from
            } else {
                to
            }
        }
    }

    pub fn next_permutation<T>(v: &mut [T]) -> bool
    where
        T: PartialOrd,
    {
        let mut pivot = v.len() - 1;
        loop {
            if pivot == 0 {
                return false;
            }
            if v[pivot] > v[pivot - 1] {
                pivot -= 1;
                break;
            }
            pivot -= 1;
        }
        let mut pivot_swap = v.len() - 1;
        while v[pivot] >= v[pivot_swap] {
            pivot_swap -= 1;
        }
        v.swap(pivot, pivot_swap);
        v[pivot + 1..].reverse();
        true
    }

    pub fn seq_compress<T>(v: &mut [T], start: T, step: T)
    where
        T: Ord + Copy + std::ops::AddAssign,
    {
        let mut buf_v = v.iter().cloned().enumerate().collect::<Vec<_>>();
        buf_v.sort_unstable_by_key(|q| q.1);
        let mut prev_val = buf_v[0].1;
        let mut new_val = start;
        for (_i, x) in buf_v.iter_mut() {
            if prev_val != *x {
                new_val += step;
                prev_val = *x;
            }
            *x = new_val;
        }
        buf_v.sort_unstable();
        for (i, x) in v.iter_mut().enumerate() {
            *x = buf_v[i].1;
        }
    }
}