#include <fstream>
#include <iostream>
using namespace std;
ifstream f("divk.in");
ofstream g("divk.out")
int v[500005];
long long s[500005];
int main()
{
    int n,a,b,k;
    f>>n>>k>>a>>b;
    if(a>b)
        swap(a,b);
    int i;
    for(i=1;i<=n;i++)
    {
        f>>v[i];
        s[i]=s[i-1]+v[i];
    }
    int rez=0,j;
    for(i=a;i<=b;i++)
        for(j=1;j<=n-i+1;j++)
            if((s[j+i-1]-s[j-1])%k==0)
                rez++;
    cout<<rez;
}