#include<bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
typedef vector <int> vi;
typedef pair<int,int> ii;
typedef long long ll;
typedef long double ld;
const int mod = 1e9 + 7;
const ll inf = 3e18 + 5;
int add(int a, int b) { return (a += b) < mod ? a : a - mod; }
int mul(int a, int b) { return 1LL * a * b % mod; }
int sub(int a, int b) { return (a -= b) < 0 ? a + mod : a; }
int main() {
ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
int n, d, m;
cin >> n >> d >> m;
vi v(m);
vector <vi> ind(n + 1);
for(int i = 0; i < m; i++) {
cin >> v[i];
ind[v[i]].push_back(i + 1);
}
sort(all(v));
int lo = 0, hi = m;
while(lo < hi) {
int mid = (lo + hi + 1) / 2;
int idx = 0;
bool ok = 1;
for(int day = 1; day <= n; day++) {
int ava = mid;
while(idx < m && ava > 0 && v[idx] <= day) {
if(day - v[idx] > d)
ok = 0;
idx++;
ava--;
}
}
if(ok)
hi = mid - 1;
else
lo = mid;
}
cout << lo + 1 << endl;
int idx = 0;
for(int day = 1; day <= n; day++) {
int ava = lo + 1;
while(idx < m && ava > 0 && v[idx] <= day) {
cout << ind[v[idx]].back() << " ";
ind[v[idx]].pop_back();
idx++;
ava--;
}
cout << 0 << "\n";
}
}
