#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
std::mt19937 rng(std::chrono::steady_clock::now().time_since_epoch().count());
const ll MOD = 1e9 + 7;
const ll INF = 1e9 + 7;
bool bipartite;
const int MAXN = 200005;
ll fact[MAXN];
ll h, c, t;
const ll NEG_INF = -1e17 - 7;
void solve()
{
int n, m, d;
cin >> n >> m >> d;
vector<int> jobs(m);
map<int, int> mp;
vector<vector<int>> arrivals(n + 1);
for (int i = 0; i < m; i++) {
cin >> jobs[i];
arrivals[jobs[i]].push_back(i + 1); // store job id by arrival day
mp[jobs[i]]++;
mp[jobs[i] + d + 1]--;
}
int ans = 0, active = 0;
for (int i = 1; i <= n; i++) {
active += mp[i];
ans = max(ans, active);
}
cout << ans << endl;
// Schedule banane ka part
vector<vector<int>> schedule(n + 1);
queue<pair<int, int>> q; // {job id, deadline}
for (int day = 1; day <= n; day++) {
// new arrivals
for (int id : arrivals[day]) {
q.push({id, day + d});
}
// remove expired
while (!q.empty() && q.front().second < day) {
q.pop();
}
// assign jobs today
int jobsToday = 0;
while (!q.empty() && jobsToday < ans) {
schedule[day].push_back(q.front().first);
q.pop();
jobsToday++;
}
}
// print schedule
for (int day = 1; day <= n; day++) {
for (int id : schedule[day]) cout << id << " ";
cout << 0 << endl;
}
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
int t;
t = 1;
while (t--) {
solve();
}
return 0;
}
