#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e6 + 25;
int n, d, m;
int a[MAXN];
bool check (int x) {
bool flag = 1;
int ptr = 1;
for (int day = 1; day <= n; day++) {
int cnt = 0;
while (ptr <= m && a[ptr] <= day && cnt + 1 <= x) {
flag &= day <= a[ptr] + d;
ptr++; cnt++;
}
}
flag &= ptr == m + 1;
return flag;
}
void cringe () {
for (int i = 1; i <= n; i++) cout << 0 << endl;
}
int main () {
ios::sync_with_stdio(0); cin.tie(0);
//freopen("rand", "r", stdin);
cin >> n >> d >> m;
for (int i = 1; i <= m; i++) cin >> a[i];
sort(a + 1, a + m + 1);
int l = 1, r = m - 1, ans = m;
while (l <= r) {
int mid = (l + r) >> 1;
if (check(mid)) {
r = mid - 1; ans = mid;
} else {
l = mid + 1;
}
}
cout << ans << '\n';
cringe();
}
