#include <bits/stdc++.h>
using namespace std;
int main()
{
#ifdef ONPC
freopen ("input.txt", "r", stdin);
#endif // ONPC
#ifndef ONPC
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#endif // ONPC
int span, delay, n;
cin >> span >> delay >> n;
vector<int> when(n), ord(n);
for (int i = 0; i < n; i++)
{
cin >> when[i];
ord[i] = i;
}
sort(ord.begin(), ord.end(), [&] (int i, int j) { return when[i] < when[j];});
auto is_ok = [&] (int num_workers)
{
int position = 0;
for (int day = 1; day <= span; day++)
{
int did_on_this_day = 0;
while (did_on_this_day < num_workers && position < n)
{
int cand = when[ord[position]];
if (day < cand)
{
break;
}
if (day > cand + delay)
{
return false;
}
position++;
did_on_this_day++;
}
}
return (position == n);
};
int low = 1, high = n, sol = -1;
while (low <= high)
{
int mid = (low + high) / 2;
if (is_ok(mid))
{
sol = mid;
high = mid - 1;
}
else
{
low = mid + 1;
}
}
assert(sol != -1);
cout << sol << "\n";
int num_workers = sol;
int position = 0;
for (int day = 1; day <= span; day++)
{
int did_on_this_day = 0;
while (did_on_this_day < num_workers && position < n)
{
int cand = when[ord[position]];
if (day < cand)
{
break;
}
if (day > cand + delay)
{
return false;
}
cout << ord[position] + 1 << " ";
position++;
}
cout << "0\n";
}
assert(position == n);
return 0;
}
