#include <bits/stdc++.h>
using namespace std;
const int M=3e5+12;
int n,d,m;
pair<int,int>a[M];
bool good(int num) {
int i=0;
int day=1;
int cnt=0;
while(i<m){
if(cnt==num){
cnt=0;
day++;
}
if(a[i].first>day){
day=a[i].first;
}
if(a[i].first+d<day){
return false;
}
i++;
cnt++;
}
return true;
}
int main() {
cin>>n>>d>>m;
for(int i=0;i<m;i++){
cin>>a[i].first;
a[i].second=i;
}
sort(a,a+m);
int l=0;
int r=m;
while(l+1<r){
int mid=(l+r)/2;
if(good(mid)){
r=mid;
}
else{
l=mid;
}
}
int cnt=0;
cout<<r<<endl;
for(int i=0;i<m;i++){
if(cnt==r){
cout<<0<<endl;
cnt=0;
}
cout<<a[i].second+1<<" ";
cnt++;
}
cout<<0<<endl;
cout<<0<<endl;
return 0;
}
