#include<bits/stdc++.h>
using namespace std;
void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
cerr << h; if(sizeof...(t)) cerr << ", ";
DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL
#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"
using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;
void setIO(string NAME = "") {
cin.tie(0)->sync_with_stdio(0);
if(sz(NAME)) {
freopen((NAME + ".in").c_str(),"r",stdin);
freopen((NAME + ".out").c_str(),"w",stdout);
}
}
const int MX = 1e6+5;
int N, D, M;
array<int,2> A[MX];
bool ok(int x, bool prans = false) {
int pt = 0;
FOR(d,1,N+1) {
F0R(_,x) {
if(pt>=M || A[pt][0] > d) break;
if(A[pt][0]+D >= d) {
assert(A[pt][0] <= d);
if(prans) cout << A[pt++][1]+1 << " ";
else pt++;
}
else return false;
}
if(prans) cout << "0\n";
}
return true;
}
void solve() {
cin>>N>>D>>M;
F0R(i,M) {
cin>>A[i][0];
A[i][1] = i;
}
sort(A,A+M);
int lo = 0, hi = M+1;
while(lo<hi) {
int mid = lo + (hi-lo)/2;
if(ok(mid)) hi = mid;
else lo = mid+1;
}
cout << lo << nl;
ok(lo, true);
}
int main() {
setIO();
int t=1;
//cin>>t;
while(t-->0) {
solve();
}
return 0;
}
