n,d,t = map(int,input().split())
*x, = map(int,input().split())
dic = {}
for xi in x:
    pi,qi = xi//d,xi%d
    if qi in dic:
        dic[qi].append(pi)
    else:
        dic[qi] = [pi]

ans = 0
for lst in dic.values():
    event = []
    for i in lst:
        event.append((i-t,1))
        event.append((i+t,2))
    event.sort()
    L = cnt = 0
    for x,v in event:
        if v==1:
            if cnt==0: L = x
            cnt += 1
        else:
            if cnt == 1: ans += x-L+1
            cnt -= 1

print(ans)