from collections import defaultdict


def f(xs: list):
    l = xs[0] - T
    r = xs[0] + T
    res = 0
    for i in range(1, len(xs)):
        if l <= xs[i] - T <= r:
            r = xs[i] + T
        else:
            res += r - l + 1
            l = xs[i] - T
            r = xs[i] + T
    res += r - l + 1
    return res


N, D, T = map(int, input().split())
X = list(map(int, input().split()))
X.sort()

d = defaultdict(list)
for x in X:
    d[x % D].append(x // D)

ans = 0
for xs in d.values():
    ans += f(xs)

print(ans)