#include<bits/stdc++.h>
using namespace std;
vector<pair<int, int>> arr;
int n, m , d;
map<int, set<int>> day;
map<int, int> mac;
bool f(int mm){
mac.clear();
day.clear();
int del = 0;
mac[1] += mm;
for(int i=0;i<m;i++){
auto it = mac.lower_bound(-1);
int r = (*it).first;
// cout<<(*it).first<<endl;
del = max(r - arr[i].first, d);
day[r].insert(arr[i].second);
mac[r + 1]++;
if(mac[r] > 1) mac[r]--;
else mac.erase(r);
}
return del <= d;
}
int main(){
cin>>n>>d>>m;
arr.resize(m);
for(int i=0;i<m;i++){
arr[i].second = i;
cin>>arr[i].first;
}
sort(arr.begin(), arr.end());
int mm;
int r = m;
int l = 1;
int ans = -1;
while(r >= l){
mm = l + (r - l)/2;
if(f(mm)){
r = mm - 1;
ans = mm;
}
else{
l = mm + 1;
}
}
f(ans);
for(auto i : day){
cout<<i.first<<" ";
for(auto t : i.second) cout<<t+1<<" ";
cout<<"0 \n";
}
}
