#include <iostream>
#include <fstream>
using namespace std;
int n,k,v[500001],a,b,i,x,q[500001],j,nr;
long long s;
int main()
{
    ifstream f("divk.in");
    ofstream g("divk.out");
    f>>n>>k>>a>>b;
    for(i=1;i<=n;i++)
    {
        f>>x;
        s=x+v[i-1];
        v[i]=s%k;
    }
    for(i=a;i<=b;i++)q[v[i]]++;
    j=b;
    for(i=b;i<=n;i++)
    {
        if(q[v[i]]>=a)nr=nr+q[v[i]]-a+1;
        if(v[i]==0)nr++;
        q[v[j]]--;j=i;
        q[v[i+1]]++;
    }
    g<<nr;
    f.close();
    g.close();
}