#include <bits/stdc++.h>
using namespace std;
pair<int, int> b[1000005];
queue<pair<int, int> > q;
int a[100005];
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, d, m, l=1, r=1e6, index=1;
cin >> n >> d >> m;
for (int i=1; i<=m; i++)
{
cin >> b[i].first;
b[i].second=i;
a[b[i].first]++;
}
sort(b+1, b+m+1);
while (l<r)
{
int mid=(l+r)/2;
bool ok=1;
for (int i=1; i<=n; i++)
{
if (a[i])
q.push({i, a[i]});
int cnt=mid;
while (q.size() && cnt>=q.front().second)
{
cnt-=q.front().second;
q.pop();
}
if (q.size())
{
if (q.front().first<=i-d)
{
ok=0;
break;
}
q.front().second-=cnt;
}
}
if (ok)
r=mid;
else
l=mid+1;
while (q.size())
q.pop();
}
cout << l << '\n';
for (int i=1; i<=n; i++)
{
while (index<=m && b[index].first==i)
{
q.push({b[index].second, 0});
index++;
}
int cnt=l;
while (q.size() && cnt)
{
cout << q.front().first << ' ';
cnt--;
q.pop();
}
cout << 0 << '\n';
}
return 0;
}
