#include <bits/stdc++.h>
using namespace std;

signed main() {
    ifstream cin("divk.in");
    ofstream cout("divk.out");
    
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int n, k, x, y; cin >> n >> k >> x >> y;
    
    vector <int> a(n + 2);
    for (int i = 1; i <= n; i ++) {
        cin >> a[i];
    }

    vector <int> s(k);
    int ans = 0;

    for (int i = 0; i <= n; i ++) {
        a[i + 1] += a[i];
        if (i - x >= 0) {
            s[a[i - x] % k] ++;
        }

        if (i - y - 1 >= 0) {
            s[a[i - y - 1] % k] --;
        }

        ans += s[a[i] % k];
    }

    cout << ans << '\n';
}