#include<bits/stdc++.h>
#define X first
#define Y second
#define all(x) begin(x), end(x)
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define FORD(i, b, a) for(int i = (b); i >= (a); i--)
#define REP(i, a, b) for (int i = (a); i < (b); i++)
#define mxx max_element
#define mnn min_element
#define SQR(x) (1LL * (x) * (x))
#define MASK(i) (1LL << (i))
#define Point Vector
#define left Left
#define right Right
#define div Div
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ld;
typedef pair<db, db> pdb;
typedef pair<ld, ld> pld;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
typedef pair<ll, ll> pll;
typedef pair<ll, pll> plll;
typedef pair<ll, int> pli;
typedef pair<ll, pii> plii;
template<class A, class B>
bool maximize(A& x, B y) {
if (x < y) return x = y, true; else return false;
}
template<class A, class B>
bool minimize(A& x, B y) {
if (x > y) return x = y, true; else return false;
}
/* END OF TEMPLATE */
const int N = 1e5 + 7;
vector<pii> query[N];
vector<int> res, ans;
int n, m, d;
bool check(int x) {
priority_queue<pii, vector<pii>, greater<pii>> pq;
ans.clear();
FOR(i, 1, n) {
for (auto x : query[i]) pq.push({x.X, x.Y});
int m = x;
// cout<<i<<" "<<pq.size()<<"\n";
while (m > 0 && !pq.empty()) {
pii tmp = pq.top();
pq.pop();
int r = tmp.X, idx = tmp.Y;
if (r < i) return false;
ans.push_back(idx);
m--;
}
ans.push_back(0);
}
if (!pq.empty()) return false;
return true;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin>>n>>d>>m;
FOR(i, 1, m) {
int x;
cin>>x;
query[x].push_back({x + d, i});
}
int d = 1, c = 0, g, result = 0;
FOR(i, 1, n) maximize(c, (int)query[i].size());
while (d <= c) {
g = (d + c) >> 1;
if (check(g)) {
result = g;
res = ans;
c = g - 1;
}
else d = g + 1;
}
cout<<result<<"\n";
for (auto x : res) cout<<x<<" \n"[x == 0];
return 0;
}
