#include <bits/stdc++.h>
#pragma GCC Optimize("O3")
#define FOR(i, x, y) for (int i = x; i < y; i++)
#define MOD 1000000007
typedef long long ll;
using namespace std;
vector<int> a[100001];
bool check(int machines, int days, int jobs, int delay, bool output) {
queue<pair<int, int>> pending;
FOR(i, 1, days + 1) {
for (int j : a[i]) pending.push({i, j});
for (int j = 0; j < machines && pending.size(); j++) {
if (i - pending.front().first > delay) return false;
if (output) cout << pending.front().second << ' ';
pending.pop();
}
if (output) cout << "0\n";
}
return true;
}
int main() {
iostream::sync_with_stdio(false);
cin.tie(0);
int n, d, m;
cin >> n >> d >> m;
FOR(i, 1, m + 1) {
int x;
cin >> x;
a[x].push_back(i);
}
int l = 1, r = m;
while (l != r) {
int mid = (l + r) / 2;
if (check(mid, n, m, d, false)) r = mid;
else l = mid + 1;
}
cout << l << '\n';
check(l, n, m, d, true);
return 0;
}
