#include <bits/stdc++.h>
using namespace std;
int main() {
int N, D, M;
cin >> N >> D >> M;
vector<int> jobRequests(M);
for (int i = 0; i < M; ++i) {
cin >> jobRequests[i];
}
vector<int> jobsPerDay(N + 1, 0);
for (int i = 0; i < M; ++i) {
jobsPerDay[jobRequests[i]]++;
}
priority_queue<int, vector<int>, greater<int>> availableMachines;
int maxMachines = 0;
vector<vector<int>> schedule(N + 1);
for (int day = 1; day <= N; ++day) {
while (!availableMachines.empty() && availableMachines.top() < day) {
availableMachines.pop();
}
for (int job = 0; job < jobsPerDay[day]; ++job) {
if (availableMachines.empty() || availableMachines.top() > day + D) {
maxMachines++;
availableMachines.push(day + D);
} else {
int nextAvailableDay = availableMachines.top();
availableMachines.pop();
availableMachines.push(nextAvailableDay + 1);
}
schedule[day].push_back(day);
}
}
cout << maxMachines << endl;
for (int day = 1; day <= N; ++day) {
for (int job : schedule[day]) {
cout << job << " ";
}
cout << "0" << endl;
}
return 0;
}
