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

int main()
{
    ifstream fcin("divk.in");
    ofstream fcout("divk.out");
    long long nr=0;
    int n,a,b,k,j,i,*s,x;
    fcin>>n>>k>>a>>b;
    s=new int[n+1];
    for (i=1;i<=n;i++)
    {
        fcin>>x;
        s[i]=s[i-1]+x;
    }
    for (i=1;i<=n-a+1;i++)
    {
        x=i+a-3;
        for (j=i+a-1;j<=i+a+b-3&&j<=n;j++)
        {
            if ((s[j]-s[x])%k==0)
                nr++;
        }
    }
    fcout<<nr<<endl;
    fcin.close();
    fcout.close();
    return 0;
}