#include <iostream>
#include <stack>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;
bool canwork (vector<pair<int,int>> rq,int mid,int &N,int &D,int command) {
int top = 0;
stack <int> num;
for (int i=1; i<=N+D; i++) {
int cnt = 0;
while (top!=rq.size()-1 && rq[top].first <= i) {
if (cnt < mid) {
if (rq[top].first <= i && i-rq[top].first > D) return false;
if (command == 1) num.push(rq[top].second);
++cnt;
++top;
}
else break;
}
if (command == 1) {
while (command == 1 && !num.empty()) {
cout << num.top() << " ";
num.pop();
}
cout << 0 << "\n";
if (i==N) break;
}
}
return true;
}
int main() {
cin.tie(0) -> ios_base::sync_with_stdio(false);
int N,D,M;
cin >> N >> D >> M;
vector <pair<int,int>> request;
int left = 1;
int right = M;
for (int i=1; i<=M; i++) {
int req;
cin >> req;
request.push_back(make_pair(req,i));
}
sort(request.begin(),request.end());
int ans=0;
while (left <= right) {
int mid = left + (right-left)/2;
if (canwork(request,mid,N,D,0)) {
right = mid-1;
ans = mid;
}
else {
left = mid+1;
}
}
cout << ans << "\n";
int top = 0;
canwork(request,ans,N,D,1);
}
