#include <bits/stdc++.h>
using namespace std;
struct Job {
int day, idx;
};
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int N, D, M;
cin >> N >> D >> M;
vector<Job> array(M);
for (int i = 0; i < M; ++i) {
cin >> array[i].day;
array[i].idx = i + 1;
}
int lo = 1, hi = M;
int best = M;
auto work = [&](int k) {
vector<int> temp(N+1, 0);
sort(array.begin(), array.end(), [](Job a, Job b){ return a.day < b.day; });
for (auto& job : array) {
bool done = false;
for (int d = job.day; d <= min(N, job.day + D); ++d) {
if (temp[d] < k) {
temp[d]++;
done = true;
break;
}
}
if (!done) return false;
}
return true;
};
while (lo <= hi) {
int mid = (lo + hi) / 2;
if (work(mid)) {
best = mid;
hi = mid - 1;
} else {
lo = mid + 1;
}
}
vector<vector<int>> ans(N+1);
vector<int> cnt(N+1, 0);
sort(array.begin(), array.end(), [](Job a, Job b){ return a.day < b.day; });
for (auto& job : array) {
for (int d = job.day; d <= min(N, job.day + D); ++d) {
if (cnt[d] < best) {
ans[d].push_back(job.idx);
cnt[d]++;
break;
}
}
}
cout << best << '\n';
for (int d = 1; d <= N; ++d) {
for (int id : ans[d]) cout << id << ' ';
cout << 0 << '\n';
}
return 0;
}
