#include<fstream>
using namespace std;

#define NN 500001
ofstream out("divk.out");

int n,A,B,k;
long long v[NN],uz[NN],ans;

void read();
void solve();

int main()
{
	read();
	solve();
	out<<ans<<'\n';
	return 0;
}

void read()
{
	ifstream in("divk.in");
	in>>n>>k>>A>>B;
	for(int x,i=1;i<=n;i++)
	{
		in>>x;
		v[i]=(v[i-1]+x)%k;
	}
	
}

void solve()
{
	for(int i=A;i<=n;i++)
	{
		++uz[v[i-A]];
		if(i>B)
			--uz[v[i-B-1]];
		ans+=uz[v[i]];
	}
}