#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define all(x) x.begin(), x.end()
int n, d, m;
vector<pair<int, int>> v;
vector<int> cur;
bool check(int x) {
queue<pair<int, int>> q;
int cnt = 0;
cur.clear();
for (int day = 1; day <= n; day++) {
if (q.size() && day - q.front().first > d) return 0;
while (cnt < m && v[cnt].first == day) q.push(v[cnt++]);
for (int i = 0; i < x && q.size(); i++) {
cur.push_back(q.front().second);
q.pop();
}
cur.push_back(0);
}
return (q.size() == 0);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> d >> m;
v.resize(m);
for (int i = 0; i < m; i++) {
cin >> v[i].first;
v[i].second = i + 1;
}
sort(all(v));
int l = 0, r = m;
vector<int> ans;
while (l + 1 < r) {
int mid = (l + r) / 2;
if (check(mid)) {
r = mid;
ans = cur;
}
else l = mid;
}
cout << r << endl;
for (auto x : ans) {
if (x != 0) cout << x << " ";
else cout << 0 << endl;
}
}
