#include <fstream>
using namespace std;
ifstream in ("divk.in");
ofstream out ("divk.out");
int v[500001],fr[100001];
int main()
{
    long long  a,b,k,n,sol=0;
    in>>n>>k>>a>>b;
    for (int i=1;i<=n;++i)
    {
        in>>v[i];
        v[i]+=v[i-1];
        v[i]%=k;
    }
    for (int i=a;i<=n;++i)
    {
        fr[v[i-a]]++;
        if (i>b)
            fr[v[i-b-1]]--;
        sol+=fr[v[i]];
    }
    out<<sol;
}