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

int N,M;
int A[100001];

vector<int> E[100000];
int I[100000];
vector<int> V;
int ans[100000];

int main(){
  scanf("%d%d",&N,&M);
  rep(i,N){ scanf("%d",&A[i]); A[i]--; }
  rep(i,N-2) if(A[i]==A[i+2]){ printf("No\n"); return 0; }
  rep(i,M) I[i]=0;
  rep(i,N-1){
    if(i%2){ E[A[i+1]].push_back(A[i]); I[A[i]]++; }
    else{ E[A[i]].push_back(A[i+1]); I[A[i+1]]++; }
  }
  queue<int> Q; rep(i,M) if(I[i]==0) Q.push(i);
  while(Q.size()){
    int p=Q.front(); Q.pop();
    V.push_back(p);
    for(int e:E[p]) if(0==--I[e]) Q.push(e);
  }
  if(V.size()!=M){ printf("No\n"); return 0; }
  printf("Yes\n");
  rep(i,M) ans[V[i]]=i+1;
  rep(i,M){ if(i) printf(" "); printf("%d",ans[i]); } printf("\n");
  return 0;
}