#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> P;
typedef vector<ll> VI;
typedef vector<VI> VVI;
#define REP(i,n) for(int i=0;i<(n);i++)
#define ALL(v) v.begin(),v.end()
constexpr ll MOD=1000000007;
constexpr ll INF=1e18;

int main(){
    int n, m; cin >> n >> m;
    VI a(n); REP(i,n) cin >> a[i], a[i]--;
    REP(i,n-2){
        if(a[i]==a[i+2]){
            cout << "No" << endl;
            return 0;
        }
    }
    VVI edge(m,VI(0)); VI h(m,0);
    REP(i,n-1){
        if(i%2==0){
            edge[a[i]].push_back(a[i+1]);
            h[a[i+1]]++;
        }
        else{
            edge[a[i+1]].push_back(a[i]);
            h[a[i]]++;
        }
    }
    queue<int> q;
    REP(i,m){
        if(h[i]==0)
            q.push(i);
    }
    VI tp;
    while(!q.empty()){
        int v=q.front();
        tp.push_back(v);
        q.pop();
        for(auto to:edge[v]){
            if(--h[to]==0)
                q.push(to);
        }
    }
    if(tp.size()!=m){
        cout << "No" << endl;
    }
    else{
        cout << "Yes" << endl;
        VI ans(m,0);
        REP(i,m){
            ans[tp[i]]=i+1;
        }
        REP(i,m){
            if(i) cout << " ";
            cout << ans[i];
        }
        cout << endl;
    }
    return 0;
}