import sys
input = sys.stdin.readline
N = int(input())

class BipartiteMatching:
  def __init__(self, n, m):
    self._n = n
    self._m = m
    self._to = [[] for _ in range(n)]

  def add_edge(self, a, b):
    self._to[a].append(b)

  def solve(self):
    n, m, to = self._n, self._m, self._to
    pre = [-1] * n
    root = [-1] * n
    p = [-1] * n
    q = [-1] * m
    upd = True
    while upd:
      upd = False
      s = []
      s_front = 0
      for i in range(n):
        if p[i] == -1:
          root[i] = i
          s.append(i)
      while s_front < len(s):
        v = s[s_front]
        s_front += 1
        if p[root[v]] != -1: continue
        for u in to[v]:
          if q[u] == -1:
            while u != -1:
              q[u] = v
              p[v], u = u, p[v]
              v = pre[v]
            upd = True
            break
          u = q[u]
          if pre[u] != -1: continue
          pre[u] = v
          root[u] = root[v]
          s.append(u)
      if upd:
        for i in range(n):
          pre[i] = -1
          root[i] = -1
    return [(v, p[v]) for v in range(n) if p[v] != -1]

dinic = BipartiteMatching(N, N)

for i in range(N):
  u, v = map(int, input().split())
  u -= 1
  v -= 1
  dinic.add_edge(i, u)
  dinic.add_edge(i, v)

flow = dinic.solve()
if len(flow) == N:
  print("Yes")
  for _, x in flow: print(x + 1)
else: print("No")