#include <bits/stdc++.h>
using namespace std;
#define int long long
#define N 500005
#define ff first
#define ss second
const int inf = 1e18;
int n, m, t;
pair <int,int> a[N];
int32_t main() {
ios::sync_with_stdio(0);cin.tie(0);
cin >> n >> m >> t;
for(int i = 1; i <= t; i++) {
cin >> a[i].ff;
a[i].ss = i;
}
sort(a + 1, a + t + 1);
int l = 1, r = 1e15;
while(l <= r) {
int mid = (l + r) / 2, cnt = 0, k = 0, ok = 0;
for(int i = 1; i <= t; i++) {
k++;
if(k == mid + 1) {
cnt++;
k = 1;
}
if(a[i].ff + m < cnt) {
ok = 1;
break;
}
}
if(ok || cnt > n) {
l = mid + 1;
}
else {
r = mid - 1;
}
}
r++;
cout << r << endl;
int cnt = 1, k = 0;
for(int i = 1; i <= t; i++) {
k++;
if(k == r + 1) {
k = 1;
cnt++;
cout << "0\n";
}
cout << a[i].ss << " ";
}
for(int i = cnt; i <= n; i++) {
cout << "0\n";
}
return 0;
}
