#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector,Ofast")
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef long double ld;
const ll N=1e6+5;
const ll MOD=1e9+7;
const ld pi=acos(-1);
#define REP(i,n) for(int i=0;i<n;++i)
#define REP1(i,n) for(int i=1;i<=n;++i)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define lwb lower_bound
#define SZ(_a) (ll)_a.size()
ll n,st[N],d,m,ans[N],lis[N];
ll que[N];
bool ck(ll k){
ll nl=0,nr=0;
for(int i=1,id=1;i<=n;i++){
while(id<=m&&st[lis[id]]==i)que[nr++]=(lis[id]),++id;
REP(j,k){
if(nr-nl==0)break;
ans[que[nl++]]=i;
}
if(nr-nl&&st[que[nl]]+d<=i)return 0;
}
return 1;
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>d>>m;
REP1(i,m){
cin>>st[i];
lis[i]=i;
}
sort(lis+1,lis+m+1,[&](ll a,ll b){
return (st[a]<st[b]);
});
//REP1(i,m)cout<<lis[i]<<st[lis[i]]<<"\n";
ll r=m,l=-1;
while(l<r-1){
ll mid=(l+r)>>1;
if(ck(mid)){
r=mid;
}else{
l=mid;
}
}
cout<<r<<"\n";
ck(r);
sort(lis+1,lis+m+1,[&](ll a,ll b){
return (ans[a]<ans[b]);
});
//REP1(i,m)cout<<lis[i]<<" "<<ans[lis[i]]<<"\n";
for(int i=1,id=1;i<=n;i++){
while(id<=m&&ans[lis[id]]==i)cout<<lis[id]<<" ",++id;
cout<<"0\n";
}
return 0;
}
/*
8 2 12
1 2 4 2 1 3 5 6 2 3 6 4
*/
