#!/usr/bin/env python3
import sys
input = sys.stdin.readline

n, d, t = map(int, input().split())
x = [int(item) for item in input().split()]

mod_dict = dict()
for item in x:
    if item % d not in mod_dict:
        mod_dict[item % d] = []
    mod_dict[item % d].append(item)
    
ans = 0
for key in mod_dict.keys():
    arr = mod_dict[key]
    event = []
    for item in arr:
        event.append((item - t * d, 1))
        event.append((item + (t + 1) * d, -1))
    event.sort()
    level = 0
    for v, c in event:
        if level == 0:
            l = v
        level += c
        if level == 0:
            ans += (v - l) // d

print(ans)