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():
    st = []
    for i in lst:
        if st and st[-1][1] <= i-t:
            st[-1][1] = i+t
    else:
        st.append([i-t,i+t])
    for L,R in st:
        ans += R-L+1

print(ans)