#include <bits/stdc++.h>
using namespace std;
int n, d, m;
vector<vector<int>> jobs(1, vector<int>(0));
bool check(int mach)
{
int day=1;
int dr=mach;
int s;
for(int i=1 ; i<=n; i++)
{
s = (int)jobs[i].size();
if(day<i)
{
day=i;
dr=mach;
}
if(s>dr)
{
s-=dr;
day++;
dr=mach;
}
else
{
dr-=s;
if(dr==0)
{
day++;
dr=mach;
}
continue;
}
day += s/mach;
dr = mach - (s%mach);
if(dr == 0) {day++; dr = mach;}
if(day>i+d || day>n) return false;
}
return true;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cin>>n>>d>>m;
jobs.resize(n+1);
int o;
for(int i=1; i<=m; i++)
{
cin>>o;
jobs[o].push_back(i);
}
int high = 1000001;
int low = 0;
int mid;
while(high-low>1)
{
mid = (high+low)/2;
if(check(mid)) high = mid;
else low = mid;
}
cout<<high<<"\n";
int num_mach = high;
int curr=1;
int cnt=0;
for(int i = 1; i<=n ; i++)
{
cnt = 0;
while((cnt<num_mach))
{
if(jobs[curr].empty())
{
while((jobs[curr].empty()))
{
curr++;
if(curr>i) break;
}
if(curr>i || curr>n-d)
{
cout<<0<<"\n";
cnt=0;
break;
}
}
cout<<jobs[curr][0]<<" ";
jobs[curr].erase(jobs[curr].begin());
cnt++;
}
if(cnt==num_mach) cout<<0<<"\n";
}
}
