#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < int(n); i++)
using ll = long long;
using P = pair<int, int>;

int main() {
    int n, m;
    cin >> n >> m;
    vector<int> a(n);
    rep(i, n) {
        cin >> a[i];
        a[i]--;
    }
    vector<vector<int>> g(m);
    vector<int> h(m);
    rep(i, n - 1) {
        if (i % 2 == 0) {
            g[a[i]].push_back(a[i + 1]);
            h[a[i + 1]]++;
        }
        else {
            g[a[i + 1]].push_back(a[i]);
            h[a[i]]++;
        }
    }
    // rep(i, m) {
    //     cout << i << " " << h[i] << "=" << " ";
    //     rep(j, g[i].size()) {
    //         cout << g[i][j] << " ";
    //     }
    //     cout << endl;
    // }
    stack<int> st;
    rep(i, m) if (h[i] == 0) st.push(i);
    vector<P> ans;
    while (!st.empty()) {
        int now = st.top(); st.pop();
        ans.push_back({now, ans.size() + 1});
        for (auto ne : g[now]) {
            h[ne]--;
            if(h[ne] == 0) {
                st.push(ne);
            }
        }
    }
    if ((int)ans.size() != m) {
        cout << "No" << endl;
    }
    else {
        cout << "Yes" << endl;
        sort(ans.begin(), ans.end());
        rep(i, m) {
            cout << ans[i].second << " ";
        }
        cout << endl;
    }
    return 0;
}