#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
struct Job {
int day, id;
};
int N, D, M;
vector<Job> jobs;
vector<int> schedule[100005];
// Berilgan K ta mashina bilan ishlarni bajarish mumkinligini tekshirish
bool check(int K, bool save_schedule) {
if (save_schedule) {
for (int i = 1; i <= N; i++) schedule[i].clear();
}
queue<Job> q;
int job_idx = 0;
for (int day = 1; day <= N; day++) {
// Shu kuni kelgan ishlarni navbatga qo'shish
while (job_idx < M && jobs[job_idx].day == day) {
q.push(jobs[job_idx]);
job_idx++;
}
// K ta mashinada ishlarni bajarish
for (int m = 0; m < K && !q.empty(); m++) {
Job current = q.front();
q.pop();
// Kechikish cheklovini tekshirish
if (day > current.day + D) return false;
if (save_schedule) {
schedule[day].push_back(current.id);
}
}
}
return q.empty();
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> N >> D >> M;
for (int i = 0; i < M; i++) {
int d;
cin >> d;
jobs.push_back({d, i + 1});
}
// Ishlarni kelgan kuni bo'yicha tartiblaymiz
sort(jobs.begin(), jobs.end(), [](Job a, Job b) {
return a.day < b.day;
});
// Binary search orqali minimal mashinalar sonini topish
int low = 1, high = M, ans = M;
while (low <= high) {
int mid = low + (high - low) / 2;
if (check(mid, false)) {
ans = mid;
high = mid - 1;
} else {
low = mid + 1;
}
}
// Optimal natija bilan jadvalni qayta hisoblash
cout << ans << "\n";
check(ans, true);
for (int i = 1; i <= N; i++) {
for (int id : schedule[i]) {
cout << id << " ";
}
cout << "0\n";
}
return 0;
}
