#include <fstream>

using namespace std;

ifstream ci ("divk.in");
ofstream co ("divk.out");

int nr[100001];

int main()
{
    int n,a,b,k;
    ci >> n >> k >> a >> b;
    int v[n+1];
    v[0]=0;
    for (int i=1; i<=n; i++)
    {
        ci >> v[i];
        v[i]=v[i]+v[i-1];
        v[i]=v[i]%k;
    }
    int r=0;
    for (int i=a; i<=b; i++)
    {
        nr[v[i-a]]++;
        r+=nr[v[i]];
    }
    for (int i=b+1; i<=n; i++)
    {
        nr[v[i-a]]++;
        nr[v[i-b-1]]--;
        r+=nr[v[i]];
    }
    co << r;
    return 0;
}