#define ll long long
#include <bits/stdc++.h>
using namespace std;
ll inf = 999999999999999999;
/*
Job Scheduling
*/
void solve(istream& cin = std::cin, ostream& cout = std::cout){
int n,d,jobs; cin >> n >> d >> jobs;
vector<vector<int>> nums(n);
int num;
for (int i = 0; i < jobs; i++){
cin >> num;
nums[num-1].push_back(i);
}
queue<int> q;
int l=1,r=jobs,m, sol = r;
bool a;
while (l <= r){
m = (l+r)/2;
a = true;
q = {};
for (int i = 0; i < n; i++){
for (int j = 0; j < nums[i].size(); j++){
q.push(nums[i][j]+d);
}
for (int j =0 ; j < m; j++){
if (q.empty()){break;}
else {
if (q.front() < i){a=false;}
q.pop();
}
}
}
if (a){
sol = m, r=m-1;;
}
else {l=m+1;}
}
cout << sol << '\n';
q = {};
for (int i = 0; i < n; i++){
for (int j = 0; j < nums[i].size(); j++){
q.push(nums[i][j]);
}
for (int j= 0; j < sol; j++){
if (q.empty()){break;}
cout << q.front()+1 << " ";
q.pop();
}
cout << "0";
if (i < n-1){cout << "\n";}
}
}
// ------------------------------
bool fileExists(const std::string& filename) {
std::ifstream file(filename);
return file.good();
}
int main() {
ios::sync_with_stdio(0);
cout.tie(0);
cin.tie(0);
string f = "angry";
if (fileExists(f+".in")){
ifstream cin(f+".in"); ofstream cout(f+".out");
solve(cin,cout);
cin.close(),cout.close();
}
else if (fileExists("input.txt")){
ifstream cin("input.txt"); ofstream cout("output.txt");
solve(cin,cout);
cin.close(), cout.close();
}
else {
solve();
}
}
