#include <iostream>
#include <fstream>

using namespace std;

int main() {
    ifstream f("divik.in");
    ofstream g("divik.out");
    long long n,a,b,k,sir[500002],contor=0;
    sir[0]=0;
    f>>n>>k>>a>>b;
    for(int i=1;i<=n;i++) {
        f>>sir[i];
        sir[i]=sir[i-1]+sir[i];
    }
    long long j=a;
    while(j<=b) {
        for(int i=j;i<=n;i++) {
            if((sir[i]-sir[i-j])%k==0) {
                contor++;
            }
        }
        j++;
    }
    g<<contor;
    f.close();
    g.close();
}