#include<stdio.h>

long a, b, n, k, v[500000], contor, s[500000];

void citire()
{
  long i;
  freopen("divk.in","r",stdin);
  freopen("divk.out","w",stdout);

  scanf("%ld %ld %ld %ld",&n, &k, &a, &b);
  for (i=1; i<=n; i++){ scanf ("%ld",&v[i]); s[i]=s[i-1]+v[i];}
}

void calcul()
{
  long i, j;
  for (i=1; i<=n-a+1; i++)
    for (j=i+a-1; j<=n; j++)
      if (s[i]%k==s[j]%k) contor++;
  printf("%ld",contor);
}

int main()
{
  citire();
  calcul();
  return 0;
}