#include <algorithm>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <iostream>
#include <numeric>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <functional>
#include <iomanip>
using namespace std;
using ll = long long;

class range {private: struct I{int x;int operator*(){return x;}bool operator!=(I& lhs){return x<lhs.x;}void operator++(){++x;}};I i,n;
public:range(int n_):i({0}),n({n_}){}range(int i_,int n_):i({i_}),n({n_}){}I& begin(){return i;}I& end(){return n;}};


template<class T, class U> ostream& operator<<(ostream& os, const pair<T, U>& p){ return os << "{" << p.first << ", " << p.second << "}"; }
template<typename T> ostream& operator<<(ostream& os, const vector<T>& obj) { os << "{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }
template<typename T> ostream& operator<<(ostream& os, const set<T>& obj) { os << "set{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }
template<typename T, typename U> ostream& operator<<(ostream& os, const map<T, U>& obj) { os << "map{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }

#ifdef ONLINE_JUDGE
#define dump(expr) ;
#else
#define dump(expr) { cerr << "\033[33m#L" << __LINE__ << ": " << expr << "\033[39m" << endl; }
#endif

struct E {
  int fr, to;
  E(int fr_, int to_) : fr(fr_), to(to_) {}
  friend ostream &operator<<(ostream &os, const E &e) { os << "(" << e.fr << " -> " << e.to << ")"; return os; }
};
typedef vector<E> V;

void add_edge(vector<V> &vg, int fr, int to) {
  vg[fr].push_back(E(fr, to));
}

void solve() {
  int c, n; cin >> c >> n;
  vector<int> constraints(c);
  for (int i : range(c)) cin >> constraints[i];

  vector<V> vg(n);
  for (int i : range(c - 1)) {
    int a = constraints[i] - 1;
    int b = constraints[i + 1] - 1;
    if (i % 2) swap(a, b);
    add_edge(vg, a, b);
  }
  dump(vg);

  vector<int> val(n);

  int gid = 1;
  function<int(int)> dfs;
  dfs = [&](int idx) {
    if (val[idx] > 0) return val[idx];
    if (val[idx] == -1) {
      return -1;
    }

    val[idx] = -1;

    for (auto e : vg[idx]) {
      int child = dfs(e.to);
      if (child == -1) return -1;
    }
    val[idx] = gid++;
    return val[idx];
  };

  for (int i : range(n)) if (dfs(i) == -1) {
    cout << "No" << endl;
    return;
  }

  vector<int> xs(c);
  for (int i : range(c)) xs[i] = val[constraints[i] - 1];
  dump(xs);

  for (int i : range(c - 2)) if (xs[i] == xs[i + 2]) {
    cout << "No" << endl;
    return;
  }

  cout << "Yes" << endl;
  for (int i : range(n)) cout << val[i] << " ";
  cout << endl;
}

int main() {
  cout << fixed << setprecision(12);
  solve();
}