import java.io.*;
import java.util.*;
public class jobs {
static final int MAXN = 100001; // Upper bound for efficient limits
static int[] Cn; // Store job counts per day
static List<Integer>[] Req; // Compact storage for job requests
static int n, m, d;
public static boolean test(int k) {
int dd = 1, r = 0;
for (int x = 1; x <= n; x++) {
if (Cn[x] == 0) continue;
if (dd < x - d) {
dd = x - d;
r = 0;
}
dd += (Cn[x] + r) / k;
r = (Cn[x] + r) % k;
if (dd > x + 1 || (dd == x + 1 && r > 0)) {
return false;
}
}
return true;
}
@SuppressWarnings("unchecked")
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer(br.readLine());
n = Integer.parseInt(st.nextToken());
d = Integer.parseInt(st.nextToken());
m = Integer.parseInt(st.nextToken());
Cn = new int[n + 1]; // Only allocate for required days
Req = new ArrayList[n + 1]; // Compact list of job indices
for (int x = 0; x <= n; x++) {
Req[x] = new ArrayList<>();
}
for (int i = 1; i <= m; i++) {
if (!st.hasMoreTokens()) {
st = new StringTokenizer(br.readLine());
}
int a = Integer.parseInt(st.nextToken()) + d;
if (a <= n) { // Only store valid job requests within bounds
Req[a].add(i);
Cn[a]++;
}
}
// Compute lower and upper bounds for binary search
int left = 1, sol = m, r = 0;
for (int x = 1; x <= n; x++) {
if (Cn[x] == 0) continue;
int bound = (Cn[x] + d) / (d + 1);
left = Math.max(left, bound);
}
while (left < sol) {
int mid = (left + sol) / 2;
if (test(mid)) {
sol = mid;
} else {
left = mid + 1;
}
}
System.out.println(sol);
// Output the schedule
StringBuilder output = new StringBuilder();
int dc = 1, dd = 1, x = 1;
Iterator<Integer> p = Req[1].iterator();
while (dd <= n) {
if (!p.hasNext()) {
x++;
while (x <= n && Req[x].isEmpty()) x++;
if (x > n) break;
p = Req[x].iterator();
}
if (dd < x - d) {
output.append("0\n");
dd++;
dc = 1;
} else {
output.append(p.next()).append(" ");
if (++dc > sol) {
dc = 1;
dd++;
output.append("0\n");
}
}
}
if (dc > 1) {
dd++;
output.append("0\n");
}
while (dd++ <= n) {
output.append("0\n");
}
System.out.print(output);
}
}
