#ifdef _BELUGA
#include "DEBUG.h"
#else
#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 debug(...)
#endif
#define int long long
// #define endl '\n'
#define sz(a) (int)((a).size())
#define all(a) (a).begin(),(a).end()
#define allr(a) (a).rbegin(),(a).rend()
#define mem0(a) memset(a, 0, sizeof(a))
#define mem1(a) memset(a, -1, sizeof(a))
#define uniq(a) (a).erase(unique(all(a)),(a).end())
#define sum(a) accumulate(all(a), 0ll)
#define rotl(x, a) rotate(x.begin(), x.begin()+(a%sz(x)), x.end())
#define rotr(x, a) rotate(x.begin(), x.begin()+sz(x)-(a%sz(x)), x.end())
#define ppc(x) __builtin_popcountll(x)
#define type(x) remove_reference<decltype(x)>::type
typedef vector<int> vi;
typedef set<int> si;
typedef multiset<int> msi;
typedef map<int, int> mii;
typedef pair<int, int> pii;
const double pi = 3.141592653589793;
void google() { static int _gtest_ = 1; cout << "Case #" << _gtest_++ << ": "; }
mt19937 rngi(chrono::steady_clock::now().time_since_epoch().count());
int rng() { return uniform_int_distribution<int>(1, numeric_limits<int>::max())(rngi); }
template<typename T1, typename T2>istream& operator>>(istream& in, pair<T1, T2>& a) { return in >> a.first >> a.second; }
template<typename T1, typename T2>ostream& operator<<(ostream& out, pair<T1, T2> a) { return out << a.first << " " << a.second; }
template<typename T>istream& operator>>(istream& in, vector<T>& a) { for (auto& e : a) in >> e ; return in; }
template<typename T>void print(T t) { cout << t; }
template<typename T, typename... Args>void print(T t, Args... args) { cout << t << " "; print(args...); }
template<typename... Args>void printl(Args... args) { print(args...); cout << endl; }
signed main()
{
int test = 1;
ios_base::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
cout << setprecision(3) << fixed;
// cin >> test;
// void calc(); calc();
void code(); while (test--) code();
}
const int mod = 998244353 ^ 1755654; // Confirm It.
const int maxn = 2e5 + 10; // This as well.
void code()
{
int n,d,m;
cin>>n>>d>>m;
vector<pii> vp;
int h;
for (int i = 0; i < m; ++i)
{
cin>>h;
vp.push_back({h, i+1});
}
sort(all(vp));
debug(vp);
auto check = [&](int k)
{
int jj=0;
int cc=0;
for (int i = 1; i <= n-d; ++i)
{
cc=0;
while(jj<m && vp[jj].first <= i && cc<k)
{
if (vp[jj].first+d < i) return 0;
cc++;
jj++;
}
debug(jj);
}
debug(k);
return 1;
};
int l=1, r=m;
while(l<r)
{
int mid = (l+r)/2;
if (check(mid))
r=mid;
else
l=mid+1;
}
printl(l);
reverse(all(vp));
for (int i = 0; i < n; ++i)
{
h=l;
while(h && sz(vp))
print(vp.back().second, ""), vp.pop_back(),h--;
printl(0);
}
}
