import sys
input=lambda: sys.stdin.readline().rstrip()
n,d,t=map(int,input().split())
X=[int(i) for i in input().split()]
import collections
D=collections.defaultdict(list)
for x in X:
  D[x%d].append(x)
ans=0
for x in D.keys():
  A=sorted(D[x])
  prev_l=-10**20
  prev_r=-10**20
  for a in A:
    if a-d*t>prev_r+d:
      if prev_l!=prev_r:
        ans+=(prev_r-prev_l)//d+1
      prev_l=a-d*t
      prev_r=a+d*t
    else:
      prev_r=a+d*t
  ans+=(prev_r-prev_l)//d+1
print(ans)