n, d, t = map(int, input().split())
from collections import defaultdict
dic = defaultdict(list)
for x in map(int, input().split()):
    xq, xr = divmod(x, d)
    dic[xr].append(xq)
ans = 0
for xs in dic.values():
    xs.sort()
    nxt = -10**18
    for x in xs:
        ans += x + t - max(nxt, x - t) + 1
        nxt = x + t + 1
print(ans)