import java.io.*;
import java.util.*;
class Main {
static int N, D, M;
public static void main(String[] args) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
PrintWriter writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
// Read input
StringTokenizer st = new StringTokenizer(reader.readLine());
N = Integer.parseInt(st.nextToken());
D = Integer.parseInt(st.nextToken());
M = Integer.parseInt(st.nextToken());
// Read the jobs
ArrayList<Job> jobs = new ArrayList<>();
st = new StringTokenizer(reader.readLine());
for (int i = 0; i < M; i++) {
int day = Integer.parseInt(st.nextToken());
jobs.add(new Job(day, i + 1)); // Job(day, index)
}
// Sort the jobs based on the request day
jobs.sort(Comparator.comparingInt(j -> j.day));
// Binary search for minimum number of machines
int l = 1, r = M;
ArrayList<ArrayList<Integer>> resultSchedule = null;
while (l < r) {
int mid = (l + r) / 2;
Pair<Boolean, ArrayList<ArrayList<Integer>>> feasibility = isFeasible(jobs, mid);
if (feasibility.first) {
r = mid;
resultSchedule = feasibility.second;
} else {
l = mid + 1;
}
}
// Output the result
writer.println(l);
for (ArrayList<Integer> daySchedule : resultSchedule) {
for (int jobId : daySchedule) {
writer.print(jobId + " ");
}
writer.println(0);
}
writer.close();
}
// Helper function to check if it's feasible with `machineCount` machines
static Pair<Boolean, ArrayList<ArrayList<Integer>>> isFeasible(ArrayList<Job> jobs, int machineCount) {
ArrayList<ArrayList<Integer>> schedule = new ArrayList<>();
for (int i = 0; i < N; i++) {
schedule.add(new ArrayList<>());
}
int reqNum = 0; // Index for job requests
for (int day = 1; day <= N; day++) {
for (int j = 0; j < machineCount; j++) {
// If no more jobs can be processed on this day, break
if (reqNum == M) {
return new Pair<>(true, schedule);
}
// If the job's day is after the current day, break
if (jobs.get(reqNum).day > day) {
break;
}
// Check if the job can be completed (if within deadline)
if (jobs.get(reqNum).day + D >= day) {
schedule.get(day - 1).add(jobs.get(reqNum).id);
reqNum++;
} else {
return new Pair<>(false, schedule);
}
}
}
return new Pair<>(false, schedule);
}
// Helper class to represent a job request
static class Job {
int day;
int id;
public Job(int day, int id) {
this.day = day;
this.id = id;
}
}
// Pair class to hold a pair of values (Boolean, ArrayList)
static class Pair<T, U> {
T first;
U second;
public Pair(T first, U second) {
this.first = first;
this.second = second;
}
}
}
