Photo by Johan Sannemo and Oskar Werkelin Ahlin
Having discolored his white socks in a rather beige shade
(as seen on the picture), Luktas Svettocek realised he can’t
just throw all his laundry into one machine and expect it to
retain its original colors. However, he is also too lazy to do
his laundry in several rounds. He would much rather buy more
laundry machines!
Each of Luktas’ socks have a color $D_ i$ which has a number between
$0$ and $10^9$ assigned to it. After some
experimentation, he found that he could wash any socks with a
maximum absolute color difference of $K$ in the same machine without any
discoloring. The color difference of two socks $i$ and $j$ is $D_ i  D_ j$.
Luktas now needs to know how many washing machines he needs
to wash his $S$ socks,
given that each machine can take at most $C$ socks a time.
Input
The first line consists of three integers $1 \le S, C \le 10^5$ and $0 \le K \le 10^9$, the number of
socks, the capacity of a laundry machine and the maximum color
difference, respectively. Then follow one line with
$S$ integers; these are
the color values $D_ i$ of
every sock.
Output
Output a single integer; the number of machines Luktas needs
to wash all his socks.
Sample Input 1 
Sample Output 1 
5 3 0
0 0 1 1 2

3

Sample Input 2 
Sample Output 2 
5 3 1
0 0 1 1 2

2
