#include<fstream>
using namespace std;
long int n,a,b,k,t;
long int s[500005];

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