//package USACO;
import java.io.*;
import java.util.*;
public class jobs {
public static int ans;
public static City[]arr;
public static int jobs;
public static int maxdelay;
public static int days;
static class City{
int time;
int pos;
}
static class comp implements Comparator <City> {
public int compare(City c1, City c2) {
if(c1.time < c2.time) {
return -1;
}
return 1;
}
}
public static void search(int start, int end) {
//System.out.println(start + " " + end);
if(start == end) {
ans = start;
return;
}
int mid = (start + end)/2;
if(works(mid)) {
search(start, mid);
}
else {
search(mid+1, end);
}
}
public static boolean works(int nummachines) {
int daysneeded = 1;
int val = arr[0].time;
int i = 1;
int used = 2;
while(i < jobs) {
while(i < jobs && used <= nummachines && arr[i].time <= val + maxdelay) {
i++;
used++;
}
if(i == jobs) {
break;
}
val = arr[i].time;
used = 1;
daysneeded++;
}
return daysneeded <= days;
}
public static void main(String[]args) throws IOException{
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer tokenizer = new StringTokenizer(in.readLine());
days = Integer.parseInt(tokenizer.nextToken());
maxdelay = Integer.parseInt(tokenizer.nextToken());
jobs = Integer.parseInt(tokenizer.nextToken());
ans = 0;
arr = new City[jobs];
tokenizer = new StringTokenizer(in.readLine());
for(int i = 0; i < jobs; i++) {
arr[i] = new City();
arr[i].time = Integer.parseInt(tokenizer.nextToken());
arr[i].pos = i+1;
}
Arrays.sort(arr, new comp());
search(1, 1000000);
int daysneeded = 1;
int val = arr[0].time;
int i = 1;
int startingindex = 0;
int used = 2;
System.out.println(ans);
while(i < jobs) {
while(i < jobs && used <= ans && arr[i].time <= val + maxdelay) {
i++;
used++;
}
if(i == jobs) {
System.out.println(arr[startingindex].pos + " " + arr[i-1].pos + " " + 0);
break;
}
System.out.println(arr[startingindex].pos + " " + arr[i-1].pos + " " + 0);
val = arr[i].time;
used = 1;
startingindex = i;
daysneeded++;
}
for(int m = 0; m < days - daysneeded; m++) {
System.out.println("0");
}
}
}
