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