#include <bits/stdc++.h>
using namespace std;
#define int long long
#define rep(i, b) for(int i = 0; i < (int)b; i++)
#define FOR(i, a, b) for(int i = a; i < (int)b; i++)
#define dbg(v) cerr << "Line(" << __LINE__ << ") -> " << #v << " = " << (v) << endl;
#define debug(a, b) cerr << "[" << #a << ", " << #b << "] = [" << a << ", " << b << "]\n";
template<class T> inline void read(T& t){ cin >> t; }
template<class T, class... H> inline void read(T& t, H&... h){ cin >> t; read(h...); }
template<class T> inline void read(vector<T>& t){ for(auto&x : t) read(x); }
template<class T, class... H> inline void read(vector<T>& t, vector<H>&... h){ read(t); read(h...); }
template<class T> inline void wt(const T t) { cout << t; }
template<class T> inline void print(const T t){ cout << t << "\n";}
template<class T, class... H> inline void wt(const T& t, const H&... h){ cout << t; wt(h...); }
template<class T, class... H> inline void print(const T& t, const H&... h){ cout << t; cout << " "; print(h...);}
#define all(x) x.begin(), x.end()
#define pb push_back
#define sz(a) (int)a.size()
#define f first
#define s second
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0);
int n, d, m; read(n, d, m);
vector<pair<int, int>> v(m);
rep(i, m) read(v[i].f), v[i].s = i + 1;
sort(all(v));
// bs in vector v -> if(check(mid)) r = mid - 1 else l = mid + 1;
auto check = [&](int mid){
int tmp = 0, cnt = 0, ans = 0;
rep(i, m){
cnt = 0;
if(i + 1 - v[tmp].f > d || i + 1 > n) return false;
while(v[tmp].f <= i + 1 && cnt < mid && tmp < m){
tmp++, cnt++;
// assert(mid == 6);
// dbg(i);
}
if(tmp == m) break;
ans++;
}
return tmp == m && ans <= n;
};
int l = 1, r = m, res = 0;
while(l <= r){
int mid = l + r >> 1;
if(check(mid)) r = mid - 1, res = mid;
else l = mid + 1;
}
print(res);
int tmp = 0, cnt = 0;
rep(i, n){
cnt = 0;
if(tmp <= m){
while(v[tmp].f <= i + 1 && cnt < res && tmp < m){
wt(v[tmp++].s, ' '); cnt++;
}
}
print(0);
}
return 0;
}
