#include<stdio.h>

int main ()

{
  int n,a, i,trbr,pbr,br=0;
  scanf("%d%d", &n, &a);
  for (i=1; i<=n; i++)
  {
   printf("Uneti broj: ");
   scanf("%d", &trbr);
   if(trbr+a== pbr || trbr-a == pbr)
     br++;
   pbr=trbr;
  }
  printf("%d \n",br);
  return 0;
  }