#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template <class t, class u>
void chmax(t& first, u second) {
  if (first < second) first = second;
}
template <class t, class u>
void chmin(t& first, u second) {
  if (second < first) first = second;
}
template <class t>
using vc = vector<t>;
template <class t>
using vvc = vc<vc<t>>;
using pi = pair<int, int>;
using vi = vc<int>;
template <class t, class u>
ostream& operator<<(ostream& os, const pair<t, u>& p) {
  return os << "{" << p.first << "," << p.second << "}";
}
template <class t>
ostream& operator<<(ostream& os, const vc<t>& v) {
  os << "{";
  for (auto e : v) os << e << ",";
  return os << "}";
}
using uint = unsigned;
using ull = unsigned long long;
template <class t, size_t n>
ostream& operator<<(ostream& os, const array<t, n>& first) {
  return os << vc<t>(first.begin(), first.end());
}
template <int i, class T>
void print_tuple(ostream&, const T&) {}
template <int i, class T, class H, class... Args>
void print_tuple(ostream& os, const T& t) {
  if (i) os << ",";
  os << get<i>(t);
  print_tuple<i + 1, T, Args...>(os, t);
}
template <class... Args>
ostream& operator<<(ostream& os, const tuple<Args...>& t) {
  os << "{";
  print_tuple<0, tuple<Args...>, Args...>(os, t);
  return os << "}";
}
template <class t>
void print(t x, int suc = 1) {
  cout << x;
  if (suc == 1) cout << "\n";
  if (suc == 2) cout << " ";
}
ll read() {
  ll i;
  cin >> i;
  return i;
}
vi readvi(int n, int off = 0) {
  vi v(n);
  for (int i = int(0); i < int(n); i++) v[i] = read() + off;
  return v;
}
template <class T>
void print(const vector<T>& v, int suc = 1) {
  for (int i = int(0); i < int(v.size()); i++)
    print(v[i], i == int(v.size()) - 1 ? suc : 2);
}
string readString() {
  string s;
  cin >> s;
  return s;
}
template <class T>
T sq(const T& t) {
  return t * t;
}
void yes(bool ex = true) {
  cout << "Yes"
       << "\n";
  if (ex) exit(0);
}
void no(bool ex = true) {
  cout << "No"
       << "\n";
  if (ex) exit(0);
}
void possible(bool ex = true) {
  cout << "Possible"
       << "\n";
  if (ex) exit(0);
}
void impossible(bool ex = true) {
  cout << "Impossible"
       << "\n";
  if (ex) exit(0);
}
constexpr ll ten(int n) { return n == 0 ? 1 : ten(n - 1) * 10; }
const ll infLL = LLONG_MAX / 3;
const int inf = INT_MAX / 2 - 100;
int topbit(signed t) { return t == 0 ? -1 : 31 - __builtin_clz(t); }
int topbit(ll t) { return t == 0 ? -1 : 63 - __builtin_clzll(t); }
int botbit(signed first) { return first == 0 ? 32 : __builtin_ctz(first); }
int botbit(ll first) { return first == 0 ? 64 : __builtin_ctzll(first); }
int popcount(signed t) { return __builtin_popcount(t); }
int popcount(ll t) { return __builtin_popcountll(t); }
bool ispow2(int i) { return i && (i & -i) == i; }
ll mask(int i) { return (ll(1) << i) - 1; }
bool inc(int first, int second, int c) {
  return first <= second && second <= c;
}
template <class t>
void mkuni(vc<t>& v) {
  sort(v.begin(), v.end());
  v.erase(unique(v.begin(), v.end()), v.end());
}
ll rand_int(ll l, ll r) {
  static mt19937_64 gen(chrono::steady_clock::now().time_since_epoch().count());
  return uniform_int_distribution<ll>(l, r)(gen);
}
template <class t>
void myshuffle(vc<t>& first) {
  for (int i = int(0); i < int(int(first.size())); i++)
    swap(first[i], first[rand_int(0, i)]);
}
template <class t>
int lwb(const vc<t>& v, const t& first) {
  return lower_bound(v.begin(), v.end(), first) - v.begin();
}
template <class t>
struct scc {
  const int n;
  const vvc<int>& g;
  vi ord, low, bl, st;
  int s, head;
  vvc<int> idx, gr;
  void dfs(int v) {
    ord[v] = low[v] = head++;
    st.push_back(v);
    for (auto to : g[v]) {
      if (ord[to] == -1) {
        dfs(to);
        chmin(low[v], low[to]);
      } else if (bl[to] == -1)
        chmin(low[v], ord[to]);
    }
    if (ord[v] == low[v]) {
      int c = idx.size();
      idx.emplace_back();
      while (1) {
        int first = st.back();
        st.pop_back();
        bl[first] = c;
        idx.back().push_back(first);
        if (v == first) break;
      }
    }
  }
  scc(const vvc<t>& gg, bool cgr = true)
      : n(gg.size()), g(gg), ord(n, -1), low(n, -1), bl(n, -1) {
    head = 0;
    for (int i = int(0); i < int(n); i++)
      if (ord[i] == -1) dfs(i);
    s = idx.size();
    for (int i = int(0); i < int(n); i++) bl[i] = s - 1 - bl[i];
    reverse(idx.begin(), idx.end());
    if (cgr) {
      vc<bool> u(s);
      gr.resize(s);
      for (int i = int(0); i < int(s); i++) {
        for (auto v : idx[i]) {
          for (auto to : g[v])
            if (bl[v] < bl[to]) {
              if (!u[bl[to]]) gr[bl[v]].push_back(bl[to]);
              u[bl[to]] = 1;
            }
        }
        for (auto v : idx[i])
          for (auto to : g[v]) u[bl[to]] = 0;
      }
    }
  }
};
struct twosat {
  int n;
  vvc<int> g;
  twosat(int nn) : n(nn), g(n * 2) {}
  void add(int x, int y) {
    g[x ^ 1].push_back(y);
    g[y ^ 1].push_back(x);
  }
  vi solve() {
    scc<int> s(g, false);
    for (int i = int(0); i < int(n); i++)
      if (s.bl[i * 2] == s.bl[i * 2 + 1]) return {};
    vi res(n, -1);
    for (int i = int(s.s) - 1; i >= int(0); i--)
      for (auto j : s.idx[i])
        if (res[j / 2] == -1) res[j / 2] = j % 2;
    return res;
  }
};
signed main() {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(20);
  int n, m;
  cin >> n >> m;
  vvc<int> first(n);
  for (int i = int(0); i < int(n); i++) {
    int k;
    cin >> k;
    first[i] = readvi(k, -1);
  }
  twosat x(m);
  for (int i = int(0); i < int(n - 1); i++) {
    int f = -1;
    for (int j = int(0);
         j < int(min(int(first[i].size()), int(first[i + 1].size()))); j++)
      if (first[i][j] != first[i + 1][j]) {
        f = j;
        break;
      }
    if (f == -1) {
      if (int(first[i].size()) > int(first[i + 1].size())) {
        no();
      }
    } else {
      void(0);
      x.add(first[i][f] * 2 + 1, first[i + 1][f] * 2);
      if (first[i][f] > first[i + 1][f]) {
        void(0);
        x.add(first[i][f] * 2 + 1, first[i][f] * 2 + 1);
        x.add(first[i + 1][f] * 2, first[i + 1][f] * 2);
      }
    }
  }
  vi y = x.solve();
  if (int(y.size()) == 0) no();
  vi ans;
  for (int i = int(0); i < int(m); i++)
    if (y[i]) ans.push_back(i + 1);
  yes(0);
  print(int(ans.size()));
  print(ans);
}
