#include <fstream>

using namespace std;

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

const int vmax=500000;
int v[vmax+1];

int main()
{
    int n,a,b,k;
    ci >> n >> k >> a >> b;
    for (int i=1; i<=n; i++)
    {
        ci >> v[i];
        v[i]=v[i]%k;

    }
    int r=0;
    for (int i=1; i<=n; i++)
    {
        for (int j=a; j<=b; j++)
        {
            if (v[i]==v[i+j])
                r++;
        }
    }
    co << r;
    return 0;
}