#ifdef __AVX2__
#pragma GCC target "avx2"
#endif
#pragma GCC optimize "O3"
#pragma GCC optimize "unroll-loops"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
// #define int long long
#define elif else if
#define all(l) begin(l),end(l)
#define rall(l) rbegin(l),rend(l)
#define append push_back
#define print(l) for(auto i:l) cout<<i<<' '; cout<<endl;
#define pprint(a,b) cout<<a<<' '<<b<<endl;
#define inp(l) for(auto &i:l) cin>>i;
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define pai make_pair
// #define endl "\n"
#define pii pair<int,int>
#define fi first
#define se second
#define vec vector
// const int mod=998244353;
const int mod1=998244353;
const int mod=1e9+7;
const int N=2e5+5;
int iter=1,itera=1;
void solve(){
int n,d,k;
cin>>n>>d>>k;
vec<vec<int>>ind(n+1);
vec<int>a(k);
inp(a);
for(int i=1;i<=k;i++){
ind[a[i-1]].append(i);
}
for(auto &i:ind) reverse(all(i));
vec<int>c(n+1,0);
for(auto i:a) c[i]++;
int l=0,r=k+1;
vec<int>c1;
while(l+1<r){
int m=(l+r)/2;
int x=1,rem=m;
c1=c;
bool f=1;
for(int i=1;i<=n;i++){
if(x<i){
x=i;
rem=m;
}
int ma=0;
while(c1[i]>0){
int g=min(c1[i],rem);
rem-=g;
c1[i]-=g;
ma=max(ma,x);
if(rem==0){
x++;
rem=m;
}
}
if(ma>i+d) f=0;
}
if(f) r=m;
else l=m;
}
vec<vec<int>>ans(n+1);
int x=1,rem=r;
for(int i=1;i<=n;i++){
if(x<i){
x=i;
rem=r;
}
int ma=0;
while(c[i]>0){
int g=min(c[i],rem);
rem-=g;
c[i]-=g;
for(int j=0;j<g;j++){
ans[x].append(ind[i].back());
ind[i].pop_back();
}
if(rem==0){
ma=max(ma,x);
x++;
rem=r;
}
}
}
cout<<r<<endl;
for(int i=1;i<=n;i++){
print(ans[i])
cout<<"0\n";
}
}
signed main(){
// freopen("","r",stdin);
// freopen("","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cout<<fixed<<setprecision(20);
// cin>>itera;
for(iter=1;iter<=itera;iter++) solve();
}
