#include <cstdio>
#include <fstream>

#define maxn 500010
using namespace std;

ifstream fin ("divk.in");
ofstream fout ("divk.out");

int N, K, a, b, A[maxn], px, py, i, j;
long long sol;
long S[maxn];
int main ()
{

	fin >> N >> K >> a >> b;

	for (i = 1; i <= N; i++) {
		fin >> A[i];
		S[i] = S[i - 1] + A[i];
	}
	for (i = 1; i <= N; i++) {

		px = i + a - 1;
		py = i + b - 1;

		for (j = px; j <= py && j <= N; j++)
			if ((S[j] - S[i - 1]) % K == 0) 
				++sol;
	}
	fout << sol <<"\n";
	return 0;
}