#include <iostream>
#include <algorithm>
using namespace std;
#define X first
#define Y second
pair<int, int> arr[1000001];
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int n, d, m;
cin >> n >> d >> m;
for(int i = 0; i < m; i++)
{
cin >> arr[i].X;
arr[i].Y = i+1;
}
sort(arr, arr+m);
int l = 0, r = m;
while(l < r)
{
int mid = (l+r) / 2;
int pos = 0, i = 0;
bool ok = 1;
for(int days = 1; days <= n && ok; days++)
{
for(i = pos; i < pos+mid && i < m; i++)
{
if(arr[i].X > days)
break;
if(arr[i].X + d < days)
{
ok = 0;
break;
}
}
pos = i;
if(pos == m)
break;
}
if(ok && pos == m)
r = mid;
else
l = mid+1;
}
cout << l << '\n';
int pos = 0, i = 0;
for(int days = 1; days <= n; days++)
{
for(i = pos; i < pos+l && i < m; i++)
{
if(arr[i].X <= days)
cout << arr[i].Y << ' ';
else
break;
}
cout << "0\n";
pos = i;
if(pos == m)
continue;
}
}
