#include<bits/stdc++.h>
using namespace std;
//#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
#define vec vector<ll>
#define mat vector<vector<ll> >
#define fi first
#define se second
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
typedef long double ld;
typedef complex<double> Complex;
const ll INF=1e9+7;
const ll inf=INF*INF;
const ll mod=998244353;
const ll MAX=100010;



signed main(){
    ll n,m;cin>>n>>m;
    vector<ll>a(n);
    rep(i,n){
        cin>>a[i];
        a[i]--;
    }
    bool f=1;
    rep(i,n){
        if(i+1<n)if(a[i+1]==a[i])f=0;
        if(i+2<n)if(a[i+2]==a[i])f=0;
    }
    vector<vector<ll> >G(m);
    vector<ll>d(m);
    rep(i,n){
        if(i%2==0){
            if(i+1<n){
                G[a[i]].pb(a[i+1]);
                d[a[i+1]]++;
            }
            if(i-1>=0){
                G[a[i]].pb(a[i-1]);
                d[a[i-1]]++;
            }
        }
    }
    queue<ll>q;
    rep(i,m){
        if(d[i]==0)q.push(i);
    }
    vector<ll>ans(m);
    ll now=1;
    while(!q.empty()){
        ll k=q.front();
        q.pop();
        ans[k]=now;now++;
        for(auto e:G[k]){
            d[e]--;
            if(d[e]==0)q.push(e);
        }
    }
    if(now!=m+1)f=0;
    if(!f){
        cout<<"No"<<endl;
    }else{
        cout<<"Yes"<<endl;
        rep(i,m){
            cout<<ans[i]<<' ';
        }
        cout<<endl;
    }
}