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

N, D, T = map(int, input().split())
X = list(map(int, input().split()))
ans = 0
dic = defaultdict(list)
for x in X:
    dic[x%D].append((x-D*T, x+D*T))
for _, v in dic.items():
    intervals = []
    v.sort()
    for l, r in v:
        if intervals and l <= intervals[-1][1]:
            pl, pr = intervals.pop()
            intervals.append((pl, r))
        else:
            intervals.append((l, r))
    for l, r in intervals:
        ans += (r - l) // D + 1
print(ans)