#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define vl vector<ll>
#define vi vector<int>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define pb push_back
#define sz(v) (ll)(v.size())
#define f first
#define s second
#define pii pair<int, int>
#define pll pair<ll, ll>
using namespace std;
using namespace __gnu_pbds;
typedef tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
void solve()
{
ll n, d, m, i, j;
cin >> n >> d >> m;
ll v[m+5];
for(i = 1; i <= m; i++)
cin >> v[i];
vector<pll>vect;
for(i = 1; i <= m; i++)
vect.pb({v[i], i});
sort(all(vect));
ll l = 1, r = m, bst = m+1;
while(l <= r)
{
ll mid = (l + r) / 2;
ll k = 1;
bool fl2 = true, fl = true;
for(i = 0; i < sz(vect); i += mid)
{
for(j = i; j < min(sz(vect), i + mid); j++)
{
if(vect[j].f > k)
fl = false;
if(k - vect[j].f > d)
fl2 = false;
}
k++;
}
if(!fl)
l = mid + 1;
if(!fl2)
l = mid + 1;
else if(k - 1 > n)
l = mid + 1;
else
{
bst = mid;
r = mid - 1;
}
}
cout << bst << "\n";
ll f = 0;
for(i = 0; i < sz(vect); i += bst)
{
for(j = i; j < min(sz(vect), i + bst); j++)
cout << vect[j].s << ' ';
cout << "0\n";
f++;
}
for(i = f; i < n; i++)
cout << "0\n";
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
ll tests = 1;
//cin >> tests;
while(tests--)
{
solve();
}
}
