import java.io.*;
import java.util.*;
public class jobs {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer(br.readLine());
int n = Integer.parseInt(st.nextToken());
int d = Integer.parseInt(st.nextToken());
int m = Integer.parseInt(st.nextToken());
if (m <= 300000) {
// Use the ArrayList-based implementation for smaller cases
handleSmallCases(br, n, d, m);
} else {
// For larger cases, use the optimized quicksort-based implementation
handleLargeCases(n, d, m, br);
}
}
private static void handleSmallCases(BufferedReader br, int n, int d, int m) throws IOException {
List<Pair> a = new ArrayList<>(m + 2);
StringTokenizer st = new StringTokenizer(br.readLine());
for (int i = 1; i <= m; i++) {
a.add(new Pair(Integer.parseInt(st.nextToken()), i));
}
a.add(new Pair(1000000000, 0)); // Dummy pair for boundary
// Sort using built-in sort with natural order
a.sort(Comparator.naturalOrder());
int l = 0, r = m;
while (r - l > 1) {
int mid = (l + r) / 2;
int p = 0;
for (int i = 1; i <= n; i++) {
if (a.get(p).fr + d < i) {
break;
}
int cnt = 0;
while (cnt < mid && p < m && a.get(p).fr <= i) {
cnt++;
p++;
}
}
if (p >= m) {
r = mid;
} else {
l = mid;
}
}
System.out.println(r);
StringBuilder sb = new StringBuilder();
int p = 0;
for (int i = 1; i <= n; i++) {
int cnt = 0;
while (cnt < r && p < m && a.get(p).fr <= i) {
sb.append(a.get(p).sc).append(" ");
cnt++;
p++;
}
sb.append("0\n");
}
System.out.print(sb);
}
private static void handleLargeCases(int n, int d, int m, BufferedReader br) throws IOException {
int[] fr = new int[m + 1];
int[] sc = new int[m + 1];
StringTokenizer st = new StringTokenizer(br.readLine());
for (int i = 1; i <= m; i++) {
fr[i] = Integer.parseInt(st.nextToken());
sc[i] = i;
}
quickSort(fr, sc, 1, m);
int l = 0, r = m + 1;
while (r - l > 1) {
int mid = (l + r) / 2;
int p = 1;
for (int i = 1; i <= n; i++) {
int cnt = 0;
while (cnt < mid && p <= m && fr[p] <= i) {
cnt++;
p++;
}
}
if (p > m) {
r = mid;
} else {
l = mid;
}
}
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
bw.write(r + "\n");
int p = 1;
for (int i = 1; i <= n; i++) {
int cnt = 0;
while (cnt < r && p <= m && fr[p] <= i) {
bw.write(sc[p] + " ");
cnt++;
p++;
}
bw.write("0\n");
}
bw.flush();
}
private static void quickSort(int[] fr, int[] sc, int low, int high) {
if (low < high) {
int pivotIndex = partition(fr, sc, low, high);
quickSort(fr, sc, low, pivotIndex - 1);
quickSort(fr, sc, pivotIndex + 1, high);
}
}
private static int partition(int[] fr, int[] sc, int low, int high) {
int pivot = fr[high];
int i = low - 1;
for (int j = low; j < high; j++) {
if (fr[j] <= pivot) {
i++;
swap(fr, sc, i, j);
}
}
swap(fr, sc, i + 1, high);
return i + 1;
}
private static void swap(int[] fr, int[] sc, int i, int j) {
int tempFr = fr[i];
fr[i] = fr[j];
fr[j] = tempFr;
int tempSc = sc[i];
sc[i] = sc[j];
sc[j] = tempSc;
}
static class Pair implements Comparable<Pair> {
int fr, sc;
Pair(int fr, int sc) {
this.fr = fr;
this.sc = sc;
}
@Override
public int compareTo(Pair other) {
return Integer.compare(this.fr, other.fr);
}
}
}
