#include <fstream>

using namespace std;
ifstream cin("divk.in");
ofstream cout("divk.out");
int sum[500001];
int vc[100000];
int main()
{
    int n,a,b,rez=0,k,nr,i;
    long long s=0;
    cin>>n>>k>>a>>b;
    for(i=1;i<=n;i++)
    {
        cin>>nr;
        s+=nr;
        sum[i]=s%k;
        if(i>b)
            vc[sum[i-b]]--;
        if(i>=a)
          vc[sum[i-a+1]]++;
        rez+=vc[sum[i]];
        vc[sum[i]]++;
    }
    cout<<rez;
    return 0;
}