Problem O
Stafsetning
Languages
en
is
Benni really wanted to help with the preparation of Forritunarkeppni Framhaldsskólanna so he decided to write a few problems. Benni wrote $n$ problems in total, but in the $i$-th problem he made $s_i$ typos.
Unnar is a total grammar nerd and thus double checks the grammar and spelling of every problem. After Unnar read all the problems that Benni wrote he was absolutely astonished at how many typos there were in his problem descriptions
It will take Unnar $m$ minutes to fix each typo. Unnar is however doing his masters at Reykjavík University, writing his thesis, so he can only work on fixing typos for $k$ minutes per day.
Unnar can not work on the same typo on different days.
Input
The first line contains three integers $1 \le n,m,k \le 10^5$. The next line contains $n$ integers $1 \le s_i \le 10^9$.
Output
Print a single integer, the fewest number of days Unnar needs to fix all the typos. If Unnar will never finish instead print :(.
Scoring
|
Group |
Points |
Constraints |
|
1 |
50 |
$1 \le n,m,k,s_i \le 1\, 000$ |
|
2 |
50 |
No further constraints |
| Sample Input 1 | Sample Output 1 |
|---|---|
3 2 5 2 2 1 |
3 |
| Sample Input 2 | Sample Output 2 |
|---|---|
3 5 4 1 1 1 |
:( |
