#include <stdio.h>
#include <bits/stdc++.h>

#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)

#define file ""

using namespace std;
using ll = long long;
using ull = unsigned long long;
using str = string;
using srt = short;

const int INF = (int)1e9 + 7;
const int mod = 998244353;
const ll inf = (ll)1e18;
const ull oo = 1000000000000001;
const int N = 200005;

signed main()
{
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    ios::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr); //freopen(file".in", "r", stdin); freopen(file".out", "w", stdout);

    int n, a, b, x;
    cin >> n >> a >> b >> x;
    vector<int> dp(n + 2), arr(n);
    for (auto& it : arr)
    {
        cin >> it;
        it = (it + x - 1) / x;
    }
    int ans = 0;
    for (int i = n; i > 0; --i)
    {
        dp[i] += dp[i + 1];
        arr[i - 1] += dp[i];
        ans += max(0, arr[i - 1]);
        dp[i] -= arr[i - 1];
        dp[max(0, i - b - a - 1)] += arr[i - 1];
    }
    cout << ans << endl;
}