#include <fstream>
#include <vector>
using namespace std;

ifstream is("divk.in");
ofstream os("divk.out");

int n, a, b, k;
long long cnt;
vector<int> d;
vector<long long> sum;

int main()
{
    is >> n;
    d = vector<int>(n+1);
    sum = vector<long long>(n+1);
    is >> k >> a >> b;
    for(int i = 1; i <= n; ++i)
    {
        is >> cnt;
        sum[i] = sum[i-1] + cnt;
        sum[i] = sum[i] % k;
    }
    cnt = 0;
    for(int i = 1; i <= n; ++i)
    {
        if(i - a >= 0)
            d[sum[i-a]]++;

        if(i - b > 0)
            d[sum[i-b-1]]--;

        cnt += d[sum[i]];
    }
    os << cnt;
    is.close();
    os.close();
    return 0;
}