#include <cstdio>

int main()
{
	freopen("divk.in","r",stdin);
	freopen("divk.out","w",stdout);

	long a,b,k,n,x,i,sum=0,el[500001],nr=0;

	scanf("%ld%ld%ld%ld",&n,&k,&a,&b);
	
	for(i=1;i<=n;i++)
		scanf("%ld",el+i);

	for(i=1;i<=n-b+1;i++)
	{
		sum=el[i]%k;
		nr+=(sum==0);
		for(j=i+1;j<=i+b-1;j++)
		{
			sum = (sum + el[j] % k) % k;
			nr += (sum == 0);
		}
	}

	printf("%d",nr);

	fclose(stdin);
	fclose(stdout);

	return 0;
}