#include <fstream>
using namespace std;
ifstream in("divk.in");
ofstream out("divk.out");
int s[500001],vf[500001];
int main()
{
    int n,a,b,k,x,i,cate=0;
    in>>n>>k>>a>>b;
    for(i=1; i<=n; i++)
    {
        in>>x;
        s[i]=(s[i-1]+x)%k;
    }
    for(i=a;i<b;i++)
    {
     vf[s[i-a]]++;
     cate+=vf[s[i]];
    }
    for(;i<=n;i++)
    {
     vf[s[i-a]]++;
     cate+=vf[s[i]];
     vf[s[i-b]]--;
    }
    out<<cate;
    return 0;
}