#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vi;
typedef pair<ll, ll> pi;
typedef vector<pi> vpi;
typedef map<ll, ll> mape;
#define rep(i, a, b) for(ll i=(ll)a;i<=(ll)b;i++)
#define per(i, a, b) for(ll i=(ll)a;i>=(ll)b;i--)
#define fastio {ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);}
#define pb push_back
#define mkp make_pair
#define all(v) v.begin(), v.end()
#define gap ' '
#define ff first
#define ss second
#define pie acos(-1.0)
const ll maxn = 5e5 + 10;
const ll INF = 1e9 + 10;
const double prec = 1e-8;
vector< vi > adj(maxn, vi());
void solve()
{
ll days, delay, n;
cin >> days >> delay >> n;
vi v(n);
rep(i, 0, n-1) cin >> v[i];
vpi clone;
rep(i, 0, n-1) clone.pb(mkp(v[i], i + 1));
sort(all(clone));
ll l = 1, r = n;
priority_queue< ll, vi, greater<ll> > st;
while(l < r) {
ll mid = (l + r) / 2;
rep(i, 0, mid - 1) st.push(clone[i].ff);
bool ok = true;
rep(i, mid, n - 1) {
ll x = st.top();
st.pop();
if(x + 1 > clone[i].ff + delay) {
ok = false;
break;
}
else st.push(max(x + 1, clone[i].ff));
}
if(ok) r = mid;
else l = mid + 1;
while(!st.empty()) st.pop();
}
cout << r << endl;
rep(i, 0, r-1) {
st.push(clone[i].ff);
adj[clone[i].ff].pb(clone[i].ss);
}
rep(i, r, n-1) {
ll x = st.top();
st.pop();
ll mx = max(x + 1, clone[i].ff);
adj[mx].pb(clone[i].ss);
st.push(mx);
}
while(!st.empty()) st.pop();
rep(i, 1, days) {
for(auto y : adj[i]) cout << y << ' ';
cout << 0 << endl;
}
}
int main()
{
fastio;
//freopen("angry.in", "r", stdin);
//freopen("angry.out", "w", stdout);
ll T = 1;
//cin >> T;
while(T--) solve();
return 0;
}
/*
8 2 12
1 2 4 2 1 3 5 6 2 3 6 4
*/
