import sys
input = sys.stdin.readline
from collections import *

N, D, T = map(int, input().split())
X = list(map(int, input().split()))
X.sort()
d = defaultdict(lambda: deque([]))

for Xi in X:
    d[Xi%D].append((Xi-T*D, Xi+T*D))

ans = 0

for q in d.values():
    l, r = q.popleft()
    
    while q:
        if q[0][0]>r:
            ans += (r-l)//D+1
            l, r = q.popleft()
        else:
            r = q.popleft()[1]
    
    ans += (r-l)//D+1

print(ans)