#include <bits/stdc++.h>
using namespace std;

int main(){
  int n; cin>>n; // number of items total
  int k; cin>>k; // number of colours total 
  int p; cin>>p; // period of non-repetition

  int m; cin>>m; // number of items given

  vector<int> prev(k,-p); // last occurrence of each colour
  vector<int> freq(k,0); // total occurrences of each colour
  vector<int> v(n); // assignments of colours to knitting

  // validate the initial colours from the input saving the last
  // time each one occurred
  for (int i=0; i<m; i++){
    cin>>v[i]; --v[i];
    if (prev[v[i]]+p>i){
      cout<<"impossible"<<endl;
      return 0;
    }
    prev[v[i]]=i;
    freq[v[i]]++;
  }

  // make a queue of usable colours from those not included in the
  // input or included sufficiently long ago as to not matter
  vector<pair<int,int>> todo;
  for (int i=0; i<k; i++){
    if (prev[i]+p<=m){
      todo.emplace_back(freq[i],i);
    }
  }

  // greedily populate the rest of the list with the least-used
  // colour that is currently available
  for (int i=m; i<n; i++){
    if (i-p>=m and prev[v[i-p]]==i-p){
      todo.emplace_back(freq[v[i-p]],v[i-p]);
    }
    if (todo.empty()){
      cout<<"impossible"<<endl;
      return 0;
    }
    int best=0;
    for (int z=1; z<todo.size(); z++){
      if (todo[z]<todo[best]){
        best=z;
      }
    }
    v[i]=todo[best].second;
    todo[best]=todo.back();
    todo.pop_back();
    prev[v[i]]=i;
    freq[v[i]]++;
  }

  for (int i=0; i<n; i++){
    cout<<(v[i]+1)<<(i+1==n?'\n':' ');
  }
  return 0;
}