struct BipartitieMatching {
    graph: Vec<Vec<usize>>,
    left: usize,
    right: usize,
}

impl BipartitieMatching {
    fn new(left: usize, right: usize) -> Self {
        assert!(left > 0 && right > 0);
        BipartitieMatching {
            graph: vec![vec![]; left],
            left: left,
            right: right,
        }
    }
    fn add_edge(&mut self, a: usize, b: usize) {
        assert!(a < self.left && b <self.right);
        self.graph[a].push(b);
    }
    fn bfs(&self, used: &[bool], assign: &[Option<usize>], depth: &mut [u32]) {
        let mut que = std::collections::VecDeque::new();
        for (v, (&used, depth)) in used.iter().zip(depth.iter_mut()).enumerate() {
            if !used {
                *depth = 0;
                que.push_back(v);
            }
        }
        while let Some(v) = que.pop_front() {
            let d = depth[v] + 1;
            for &u in self.graph[v].iter() {
                if let Some(k) = assign[u] {
                    if depth[k] > d {
                        depth[k] = d;
                        que.push_back(k);
                    }
                }
            }
        }
    }
    fn dfs(&self, v: usize, it: &mut [usize], used: &mut [bool], assign: &mut [Option<usize>], depth: &[u32]) -> bool {
        let d = depth[v] + 1;
        for (k, &u) in self.graph[v].iter().enumerate().skip(it[v]) {
            let ok = assign[u].map_or(true, |k| {
                assert!(used[k]);
                depth[k] == d && self.dfs(k, it, used, assign, depth)
            });
            if ok {
                assign[u] = Some(v);
                used[v] = true;
                return true;
            }
            it[v] = k + 1;
        }
        false
    }
    fn solve(&self) -> Vec<(usize, usize)> {
        let mut used = vec![false; self.left];
        let mut assign = vec![None; self.right];
        let mut depth = Vec::with_capacity(self.left);
        let mut it = Vec::with_capacity(self.left);
        loop {
            depth.clear();
            depth.resize(self.left, std::u32::MAX / 2);
            self.bfs(&used, &assign, &mut depth);
            it.clear();
            it.resize(self.left, 0);
            let mut update = false;
            for v in 0..self.left {
                if !used[v] {
                    update |= self.dfs(v, &mut it, &mut used, &mut assign, &depth);
                }
            }
            if !update {
                break;
            }
        }
        let mut ans = vec![];
        for (r, a) in assign.into_iter().enumerate() {
            if let Some(l) = a {
                ans.push((l, r));
            }
        }
        ans
    }
}
// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------

fn run() {
    input! {
        n: usize,
        e: [(usize1, usize1); n],
    }
    let mut g = BipartitieMatching::new(n, n);
    for (i, &(a, b)) in e.iter().enumerate() {
        g.add_edge(i, a);
        g.add_edge(i, b);
    }
    let f = g.solve();
    if f.len() != n {
        println!("No");
        return;
    }
    use std::io::Write;
    let out = std::io::stdout();
    let mut out = std::io::BufWriter::new(out.lock());
    writeln!(out, "Yes").ok();
    let mut ans = vec![0; n];
    for e in f {
        ans[e.0] = e.1 + 1;
    }
    for a in ans {
        writeln!(out, "{}", a).ok();
    }
}

fn main() {
    run();
}