from collections import defaultdict,deque
import sys,heapq,bisect,math,itertools,string,queue,datetime
sys.setrecursionlimit(10**8)
INF = float('inf')
mod = 10**9+7
eps = 10**-7
def inpl(): return list(map(int, input().split()))
def inpls(): return list(input().split())

N,D,T = inpl()
xx = inpl()

d_ed = set()
d_xx = defaultdict(set)
for x in xx:
    d = x%D
    d_ed.add(d)
    d_xx[d].add(x)

ans = 0
for d in d_ed:
    tmp = 0
    brx = -INF
    for x in sorted(list(d_xx[d])):
        lx = max(x - D*T, brx + D)
        rx = x + D*T
        tmp += (rx-lx)//D+1
        brx = rx
    ans += tmp

print(ans)