#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define lld double
#define int ll
#define usaco(fname) freopen(#fname ".in","r",stdin);freopen(#fname ".out","w",stdout);
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
// const ll INF = 1e18;
const int INF = 1e9;
const int mod = 1e9+7;
const lld PI = acos(-1.0);
int di[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dj[] = {0, 0, 1, -1, 1, -1, 1, -1};
#define debug(x) cout << #x << ": " << x << endl;
#define add(a, b) a += b, a %= mod
#define mul(a, b) ((a % mod) * (b % mod)) % mod
#define all(x) x.begin(),x.end()
void solve() {
int n,d,m;cin>>n>>d>>m;
vector<pair<int, int>> a(m);
for (int i = 0; i < m; i++) cin >> a[i].first, a[i].second = i;
sort(all(a));
// vector<pair<int, int>> s;
int cnt = 0;
function<bool(int, bool)> chk = [&](int k, bool ou) {
int day = 1;
for (int i = 0; i < m;) {
int l = i;
for (;i<min(l+k, m); i++) {
if (a[i].first > day) break;
if (ou) {
cout << a[i].second+1 << " ";
}
if (a[i].first + d < day) return 0;
}
if (ou) {
cnt++;
cout << 0 << endl;
}
day++;
}
return 1;
};
int l = 1, r = m;
int ans = -1;
while (l <= r) {
int mid = (l+r)>>1;
if (chk(mid,0)) {
r = mid-1;
ans = mid;
} else l = mid+1;
}
cout << ans << endl;
chk(ans, 1);
for (int i = cnt; i < n; i++) cout << 0 << endl;
}
int32_t main() {
ios_base::sync_with_stdio(0);cin.tie(0);
int t=1;
while(t--) solve();
return 0;
}
