#include <fstream>

using namespace std;

ifstream cin("divk.in");
ofstream cout("divk.out");

long long v[500005],s[500005],k,a,b,n,cnt,x;

int main()
{
    cin >> n >> k >> a >> b;
    for(int i = 1; i <= n; i++)
    {
        cin >> x;
        x %= k;
        s[i] = (s[i - 1] + x) % k;
        if(i >= a)
        {
            v[s[i - a]]++;
            if(i > b)
            {
                v[s[i - b - 1]]--;
            }
            cnt += v[s[i]];
        }
    }
    cout << cnt;
    return 0;

}