n,d,t = map(int,input().split())
X = list(map(int,input().split()))
ans = 0
dic = {}
for x in X:
    if x%d not in dic:
        dic[x%d] = []

    dic[x%d].append(x)
    
for lis in dic.values():
    l = 0
    r = 0
    for x in lis:
        if l == r == 0:
            l = x-d*t
            r = x+d*t
            continue

        if r >= x-d*t:
            r = x+d*t
        else:
            ans += (r-l)//d+1
            l = x-d*t
            r = x+d*t
    ans += (r-l)//d+1
print(ans)