#include <bits/stdc++.h>
using namespace std;
int n,d,m,l,r,mid,ct,pt,now;
pair <int,int> a[1000005];
bool ok;
int main(){
ios::sync_with_stdio(false);
cin >> n >> d >> m;
for (int i=1;i<=m;i++){
cin >> a[i].first;
a[i].second=i;
}
sort(a+1,a+1+m);
l=1; r=m;
while (l < r){
mid=(l+r)/2; ct=0;
ok=true; pt=0;
for (int i=1;i<=n;i++){
now=0;
while (now < mid && pt+1 <= m && a[pt+1].first <= i){
pt++; now++;
if (i > a[pt].first+d){
pt=-1;
goto out;
}
}
}
out:;
if (pt == m)
r=mid;
else
l=mid+1;
}
cout << l << "\n"; pt=0;
for (int i=1;i<=n;i++){
now=0;
while (now < l && pt+1 <= m && a[pt+1].first <= i){
pt++; now++;
cout << a[pt].second << " ";
if (i > a[pt].first+d){
pt=-1;
goto out;
}
}
cout << "0\n";
}
return 0;
}
